document_title: Supernatural (season 13)

question_text: when does season 13 episode 14 of supernatural come out

text: Supernatural (season 13)

text: Cast[edit]

text: Starring[edit]

text:
Jared Padalecki as Sam Winchester
Jensen Ackles as Dean Winchester
Mark Pellegrino as Lucifer
Alexander Calvert as Jack
Misha Collins as Castiel

text: Special guest star[edit]

text:
Loretta Devine as Missouri Moseley
Jim Beaver as Bobby Singer[6]

text: Guest stars[edit]

text:
Samantha Smith as Mary Winchester
Ruth Connell as Rowena[7]
Osric Chau as Kevin Tran
Kim Rhodes as Sheriff Jody Mills
Briana Buckmaster as Sheriff Donna Hanscum
Kathryn Newton as Claire Novak
Katherine Ramdeen as Alex Jones
Clark Backo as Patience Turner
Yadira Guevara-Prip as Kaia Nieves
Christian Keyes as Michael
Keith Szarabajka as Donatello Redfield
Courtney Ford as Kelly Kline
Jeffrey Vincent Parise as Asmodeus
Lisa Berry as Billie
David Haydn-Jones as Arthur Ketch
Danneel Ackles as Sister Jo / Anael[8]
Brendan Taylor as Doug Stover
Richard Speight Jr. as Gabriel
Chad Rook as Zachariah
Felicia Day as Charlie Bradbury
Erica Cerra as Dumah

text: Episodes[edit]

text:
No.
overall
No. in
season
Title
Directed by
Written by
Original air date
Prod.
code
U.S. viewers
(millions)

265
1
"Lost and Found"
Phil Sgriccia
Andrew Dabb
October 12, 2017 (2017-10-12)
T13.20551
2.10[9]

Lucifer's son Jack seems unsure of himself and the world. Dean tries to shoot him and he knocks out both Winchesters with a sonic scream, leaving to search for his father. He ends up at a local police station and seems mostly innocent but is unsure of, and unable to control, his power. Sam and Dean follow; Dean insists on killing him but Sam sees Jack as just a child. While Dean explains what Jack is to a local officer, Jack explains he learned English from his mother and grew up quickly because she told him the world was dangerous; she also said that Castiel was the father who would protect him. Three angels show up wanting to use Jack's almost limitless power for themselves. The Winchesters banish two of them and kill the third; Jack is stabbed in the heart in the process but is unharmed by the blade. Dean agrees to take him to the bunker, but only until they can find a way to kill him. They are on their own with Chuck not answering prayers. They give Castiel and Kelly a hunter's funeral, also saying goodbye to Crowley and Mary whom they assume Lucifer killed. In the alternate world, Lucifer keeps Mary alive because he needs her for something.

266
2
"The Rising Son"
Thomas J. Wright
Eugenie Ross-Leming & Brad Buckner
October 19, 2017 (2017-10-19)
T13.20552
1.90[10]

On the way back to the bunker, the Winchesters and Jack stop at a hotel and are met by Donatello the prophet. Amara ate his soul, but he has been mentally making the moral choice ever since, and he was drawn to Jack's power. Jack reads the Bible to learn more about himself and his family. Realizing he'll need more protection, the Winchesters try to get him warding tattoos, but he reflexively attacks the tattoo artist for hurting him and his body heals the ink away. Dean takes this as proof that Jack will turn evil, while Sam thinks it's because he lacks control. Meanwhile, the final Prince of Hell, Asmodeus, takes charge of Hell until Lucifer returns, disguising himself as Donatello to trick Jack into freeing the Shedim — Hell's darkest creatures — to be a hero. The brothers and the real Donatello appear, and when Asmodeus hurts them, a flicker of Jack's power makes him flee. At the bunker, Dean admits to Jack that he will kill him if he turns bad. In the alternate world, Lucifer protects Mary, intending to trade her for Jack when they get home. They meet an alternate version of Michael, who killed his world's Lucifer. Michael is the stronger of the two, and keeps this Lucifer alive because he needs him for something.

267
3
"Patience"
Robert Singer
Robert Berens
October 26, 2017 (2017-10-26)
T13.20553
1.93[11]

Missouri Mosley (from Season 1's "Home") calls the Winchesters because a wraith with a taste for psychics is about to go after her family. Dean and Jody go to protect her son James and granddaughter Patience, who is unaware she has inherited Missouri's gift. The wraith reappears and kills Missouri, as she knew it would. James reveals he cut his mother out of his life many years ago, as he grew up fearing she would get killed and also because he couldn't forgive her after his wife Tess died after becoming sick despite Missouri saying she would be fine. The wraith attacks Patience at school and later kidnaps her from home intending to feed on her slowly. In a vision, Patience sees the wraith kill her father, Jody and Dean. She warns them and Dean kills the wraith. James and Dean think Patience should live a normal life, but Jody says it is Patience's choice and that her door is open if she needs help. Meanwhile, Sam tries to train Jack because he reminds him of his own days addicted to demon blood. Jack makes no progress, which he takes as a sign he will be evil, since his powers only work negatively. While the brothers argue over him, Jack says Castiel's name; Castiel hears this and wakes up in a void of nothingness.

268
4
"The Big Empty"
John Badham
Meredith Glynn
November 2, 2017 (2017-11-02)
T13.20554
1.82[12]

A man is killed by his dead wife. Taking the case, Sam convinces Dean to let Jack join them; also having convinced Jack to help save Mary if he can master his powers. There are no signs of a ghost or revenant. A woman is then killed by her dead son. Both victims shared a grief therapist Mia, whom the guys question pretending to be three brothers that lost their mother. Sam and Dean get into an argument about Mary; and Sam discovers Mia is a shapeshifter. Mia says she only helps people by pretending to be their loved ones to give closure, and the killer must be her ex boyfriend and fellow shapeshifter, Buddy. While Sam goes to Buddy's address, Buddy actually sneaks into Mia's office and knocks out Dean and Jack. When Mia refuses to kill them, Buddy prepares to shoot Sam when he walks into the room. Jack is able to use his powers to deflect the bullet away from Sam and throw Buddy into the wall, allowing Sam to kill him. Mia in Kelly's form tells Jack that even monsters can do good. At the bunker Dean gives Jack some approval; and wants Sam to keep believing Mary is alive, admitting that he no longer seems to believe in anything anymore. Meanwhile, Castiel is in The Empty, a place predating even God and Amara, where all angels and demons sleep forever after they die. Castiel is the first in eternity to wake up. The entity there takes Castiel's form and taunts him to go back to sleep as the entity hates being awake itself. Castiel refuses, forcing the entity to send him back to Earth.

269
5
"Advanced Thanatology"
John Showalter
Steve Yockey
November 9, 2017 (2017-11-09)
T13.20555
1.71[13]

Two teenagers explore an abandoned asylum and one of them is killed. The survivor, Shawn, is left unable to speak from trauma and taking a medical mask with him. The brothers take the case and Dean insists he will be fine but clearly isn't. Dean is unable to get Shawn to talk. Sam discovers the asylum's doctor used to lobotomize his patients and the next day Shawn disappears. At the asylum Dean burns the masks destroying the doctor but the place is still haunted; Dean kills himself to find out where the patients bodies are. Shawn was possessed to go back there through the mask and the doctor made him kill himself. A Reaper reports that Dean is in The Veil and the new Death comes to see him: Billie. As the first Reaper to die after Dean killed the old Death she took the job, wanting information on how the hole to the other universe ripped open. She sees the Winchesters as important to the universe with work to do; letting the ghosts move on and sending Dean back, stating his choices decide how he dies. Dean admits to Sam he needs a victory, and they are reunited with Castiel.

270
6
"Tombstone"
Nina Lopez-Corrado
Davy Perez
November 16, 2017 (2017-11-16)
T13.20556
1.89[14]

After meeting Castiel, Jack finds a case in Dodge City, Kansas. Dean loves all Western scene material. A local deputy is killed and his Uncle Joe, another officer, swears revenge. Questioning the local undertaker, Athena, Sam realizes they are dealing with a ghoul, whom Dean recognizes as wearing the face of the famous outlaw Dave Mather. Dave robs a bank so Athena can afford to go to school in California, she has no idea what Dave really is. The brothers, Castiel and Jack get into a shootout with Dave; Jack blasts him with power but accidentally kills a bank security guard, while Dave escapes. Castiel cannot heal the guard. As the others take Jack back, Dean and Joe investigate the local graveyard where Dave has captured Athena. Dean distracts him so Joe can shoot his head off. Dean has Joe blame the guard's death on Dave. At the bunker, despite the other three saying it was a mistake, a withdrawn Jack believes he is a monster and will end up hurting the others so he must leave; knocking them back and teleporting away.

271
7
"War of the Worlds"
Richard Speight, Jr.
Eugenie Ross-Leming & Brad Buckner
November 23, 2017 (2017-11-23)
T13.20557
1.24[15]

Castiel informs Sam and Dean that he has a meeting with an angel about Jack but says he needs to go alone. Asmodeus is unable to sense Jack, and is told that the Winchesters no longer have him. In the alternate world, Michael takes most of Lucifer's grace, using his Kevin Tran to create a portal for Lucifer's earth. Instead, Lucifer escapes and the portal closes. Lucifer arrives back in the correct time, but is greatly weakened. Meanwhile the brothers notice witches being killed. Talking to a survivor, they discover the killer is searching for Rowena and looks like Arthur Ketch. Capturing him, he claims to be Arthur's twin brother, Alexander, who turned his back on the British Men of Letters. Sam finds records of Alexander but Dean is skeptical. Castiel meets with the angel Dumah and is told the angels' population is very low and they intend to force Jack to create more angels when they find him. The angels try to capture Castiel, but Lucifer is able to scare them off. He tries to convince Castiel about the urgent threat of the other Michael, saying they need Jack's power, and he decides not to tell the Winchesters. Asmodeus then appears, deciding he is the ruler of hell, capturing them both. Tracking Castiel, the brothers are attacked by demons but are helped by Alexander; who finally admits he is Arthur. He tells them Rowena gave him a spell to cheat death in exchange for allowing her to escape after being captured by the British Men of Letters some years back, but it needs a recharge so he must find her, insinuating she survived. Dean attacks but Arthur escapes. Asmodeus locks up Lucifer and Castiel and tricks the Winchesters into thinking everything is fine; having worked with Arthur all along.

272
8
"The Scorpion and the Frog"
Robert Singer
Meredith Glynn
November 30, 2017 (2017-11-30)
T13.20558
1.73[16]

After stealing a Nephilim tracking spell from a British museum, the Crossroad Demon Barthamus offers to trade it to the Winchesters to find Jack. In exchange, Barthamus requests the Winchesters aid his minions Smash and Grab in stealing a trunk from a man named Luther Shrike. Luther has Barthamus' trunk in a vault that only Dean can open due to his previous time in Hell. The Winchesters reluctantly agree to the deal and perform a raid on Luther's property. During the raid, Luther realizes the truth and kills Grab, a demon, before being captured by the Winchesters. With the help of Smash, who is a girl named Alice who once made a deal with Barthamus and is now forced to work for him, the Winchesters are able to retrieve the trunk. To their shock, the Winchesters learn that Luther is a man who once made a deal with Barthamus to save his son only to be double-crossed. The trunk contains Barthamus' human bones, leverage with which Luther can force Barthamus to leave him alone. Barthamus kills Luther, but the Winchesters reject his deal due to Barthamus' actions. Alice kills Barthamus by burning his bones, but the spell is destroyed with him. Despite this, the Winchesters are content with how things turned out as they managed to free Alice from her deal to live a normal life and stopped Barthamus.

273
9
"The Bad Place"
Phil Sgriccia
Robert Berens
December 7, 2017 (2017-12-07)
T13.20559
1.74[17]

Jack approaches a dreamwalker named Derek Swan in order to look into the alternate reality where Mary Winchester and Lucifer were trapped. Shortly afterwards, the Winchesters learn from Sheriff Jody Mills that Derek is dead and Jack is apparently responsible. The Winchesters track down Jack shortly after he helps dreamwalker Kaia Nieves escape from a drug rehabilitation facility. Jack is revealed to be innocent in Derek's death. He reveals that he has been attempting to rescue Mary from the alternate reality, but he needs a dreamwalker in order to see the world so that he can open a portal. The Winchesters and Jack rescue Kaia from angels looking for Jack to help them repopulate their species and Dean holds Kaia at gunpoint, forcing her to help them rescue Mary. Under attack by angels, Kaia and Jack combine their powers to open a portal, disintegrating the angels at the same time. Due to Kaia's visions of another reality populated by monsters that she calls the Bad Place, the Winchesters end up in the Bad Place instead while Kaia is deposited on the side of the road and Jack finds Mary. At the same time, Patience Turner has visions of the Winchesters and Jody Mills in great danger. Against her father's wishes, Patience leaves to help and warns Jody that something terrible is coming.

274
10
"Wayward Sisters"
Phil Sgriccia
Robert Berens & Andrew Dabb
January 18, 2018 (2018-01-18)
T13.20560
1.85[18]

After completing a werewolf hunt, Claire Novak gets a call from Jody Mills that the Winchesters are missing and returns to Sioux Falls. At the same time, the Winchesters remain trapped in the Bad Place where they are ambushed by a hooded figure that apparently intends to feed them to a giant monster. Working together, Jody, Alex and Claire attempt to locate and rescue the Winchesters. They are joined by Patience Turner who warns of a vision where Claire dies. The group locates dreamwalker Kaia Nieves, but come under attack by monsters from the Bad Place, making them realize that the rift to the Bad Place is still open. With the help of Kaia and Sheriff Donna Hanscum, Jody's family locates the rift. As Claire and Kaia travel to the Bad Place to rescue the Winchesters, Jody, Alex, Patience and Donna work together to kill several attacking monsters. Claire and Kaia succeed in rescuing the Winchesters before the rift closes, but Kaia is killed by the hooded figure, the true unexpected outcome of Patience's vision. In the aftermath, Sam warns Jody that more monsters may have made it through the rift in the time that it was open and Claire mourns Kaia's death. As Claire sits down to eat dinner with her family and swears revenge on Kaia's killer, another rift opens and the hooded figure emerges. The hooded figure is revealed to be an alternate reality version of Kaia.

275
11
"Breakdown"
Amyn Kaderali
Davy Perez
January 25, 2018 (2018-01-25)
T13.20561
1.93[19]

In Oshkosh, Nebraska, Donna Hanscum's niece Wendy is kidnapped. Desperate, Donna contacts the Winchesters for help despite the fact that it appears that they are dealing with a human villain rather than a monster. The Winchesters agree to help Donna and team up with Donna, her boyfriend Officer Doug Stover and Agent Clegg of the FBI. Clegg identifies the villain as the Butterfly, a serial abductor operating in the area for the past twelve years. With the help of a trucker, Dean identifies a gas station clerk Marlon as a participant in the abduction. Marlon reveals that the kidnapped victims are butchered and their parts sold online to monsters by the Butterfly. Clegg is revealed to be the Butterfly and kidnaps Sam in order to sell off his parts to monsters. Marlon is revealed to be a vampire and turns Doug into one as well. Dean and Donna are able to use Marlon's blood to cure Doug and force Marlon to give up Clegg's location before killing him. Donna rescues Wendy and kills Clegg's accomplice while Dean kills Clegg in time to save Sam's life. In the aftermath, Doug is terrified by the discovery of the world of monsters and breaks up with Donna. Sam displays a bleak outlook on life, believing that the Winchesters and anyone they get close to will suffer a terrible end.

276
12
"Various & Sundry Villains"
Amanda Tapping
Steve Yockey
February 1, 2018 (2018-02-01)
T13.20562
1.68[20]

Dean falls under a love spell cast by Jaime Plum, a witch working with her sister Jennie to steal the Black Grimoire, the spell book the Winchesters took from the Loughlin Family. Though the Plums succeed in stealing the book, Rowena unexpectedly shows up to help despite having been believed dead for months. Rowena reveals that she was resurrected again by the precautionary spell she put in place, but took a very long time to recover from her death. Rowena is seeking the Black Grimoire as it contains a ritual that will allow her to remove the magical binding placed upon her by the Grand Coven and regain her full powers. Privately, Rowena admits to Sam that she saw Lucifer's true face and she is terrified of his inevitable return. After stealing the Black Grimorie, the Plums attempt to use it to resurrect their deceased mother, but only succeed in bringing her back as a zombie. Together the Winchesters and Rowena defeat the Plums and recover the Black Grimoire. Though the Winchesters keep the book, a sympathetic Sam allows Rowena to take the page with the ritual she needs and Rowena is able to restore her full powers. At the same time, Castiel and Lucifer form an alliance to escape Asmodeus' custody. Though they succeed, Castiel refuses to trust Lucifer or give up some of his grace to him. Castiel attacks Lucifer with an angel blade, causing him harm in his weakened state.

277
13
"Devil's Bargain"
Eduardo Sánchez
Eugenie Ross-Leming & Brad Buckner
February 8, 2018 (2018-02-08)
T13.20563
1.81[21]

Following his confrontation with Lucifer, a wounded Castiel makes his way back to the Winchesters and informs them of everything that has happened including Lucifer's return. The Winchesters realize that the demon tablet could potentially contain the spell the alternate Kevin Tran used to reopen the rift and set Prophet Donatello Redfield to work on translating it. Learning of Donatello's work, Asmodeus places Donatello under his control with an order to let him know once the spell is translated. With Lucifer becoming more human, he begins draining other angels' graces in an effort to restore his own. Along the way, Lucifer meets the angel Anael, disguised as a faith healer named Sister Jo. Lucifer and Anael form a connection while the Winchesters and Arthur Ketch, working for Asmodeus, hunt for Lucifer. Lucifer and Anael are able to avoid an attempt to kill them by Arthur. Lucifer, with a promise to help make new angels and to restore the living angels wings, becomes the ruler of Heaven again with Anael at his side. Following Lucifer's escape, Arthur proposes an alliance between himself and the Winchesters to defeat Lucifer and Michael's upcoming invasion, revealing his work for Asmodeus in the process. The Winchesters reluctantly concede that they need Arthur for now and are unaware of Donatello being under the control of Asmodeus as he translates the spell. When Arthur reports his failure to Asmodeus, Asmodeus reveals that he has acquired an Archangel Blade, the one weapon that can kill Lucifer. As well, Asmodeus has prisoner the Archangel Gabriel who has been believed dead for nearly eight years.

278
14
"Good Intentions"
P. J. Pesce
Meredith Glynn
March 1, 2018 (2018-03-01)
T13.20564
1.61[22]

While reading the demon tablet, Prophet Donatello Redfield, due to his soulless state, becomes corrupted by its power. As a result, he gives the Winchesters and Castiel what he claims is the ingredients before attacking Sam who manages to subdue him. Donatello sends Dean and Castiel after Gog and Magog in an attempt to kill them, but the attempt fails. With Donatello refusing to help, Castiel forcefully strips the information from his mind, leaving Donatello brain dead. Castiel justifies that they are fighting a war for their very survival and reveals that they need the grace of an archangel, a fruit from the Tree of Life, the seal of Solomon and the blood of a most holy man. In the Apocalypse World, Zachariah (Chad Rook) tries and fails to trick Jack into helping the angels. Working together, Jack and Mary escape Michael's fortress and are taken by Bobby Singer (Jim Beaver) to one of the few human colonies left. Bobby reveals to Mary the history of Apocalypse World and the war of extermination the angels are waging, causing Mary to realize that her own alternate self created this world by not making the deal with Azazel and having Sam and Dean. Jack is ordered exiled once his true nature is discovered, but Zachariah leads an attack on the colony before he can leave. Jack kills Zachariah and helps repel the attack on the colony, earning him acceptance. Having grown to care for the humans of Apocalypse World, Jack decides to kill Michael in order to end his war of extermination and save what's left of the human race.

279
15
"A Most Holy Man"
Amanda Tapping
Andrew Dabb & Robert Singer
March 8, 2018 (2018-03-08)
T13.20565
1.66[23]

The Winchesters realize that the blood of a most holy man likely refers to a saint and set out to find someone who has saint blood. Through a black market dealer named Margaret Astor, the Winchesters are directed to a man named Richard Greenstreet who claims to have saint's blood. Greenstreet offers to give the Winchesters the blood of Saint Ignatius if they get him the skull of Saint Peter which has recently been stolen from a monastery in Malta by a man working for Seattle mob boss Santino Scarpatti. After discovering the thief murdered, the Winchesters are apprehended by Scarpatti's henchmen and Scarpatti offers a deal where he will pay them a handsome finder's fee that they can buy the blood with if they get him the skull. Complicating matters, the Winchesters meet Father Luca Camilleri, a priest from Malta seeking the skull for altruistic reasons. The Winchesters choose to help Luca and discover that Margaret Astor had murdered the thief to auction the skull off to everyone interested. Sam joins the auction, but Greenstreet instigates a gunfight that kills Margaret, Scarpatti and their henchmen. During the fight, Luca saves Dean's life and the Winchesters learn that Greenstreet lied about having the saint's blood. Greenstreet is arrested while Luca returns home with the skull. Before Luca leaves, Sam learns that he is an apostolic protonotary supernumery, a title given by the Pope for doing good works. As a result, Luca was declared "a most holy man" by the Pope and at the Winchesters' request, gives them his blood. Afterwards, Dean displays faith for the first time that they will succeed.

280
16
"Scoobynatural"
Robert Singer
Jim Krieg & Jeremy Adams
March 29, 2018 (2018-03-29)
T13.20566
2.03[24]

After stopping a plushie that comes to life in a pawn shop and attacks, the grateful owner gives Dean a new TV for free. While testing out the TV, the Winchesters are sucked into Dean's favorite episode of Scooby-Doo, Where Are You! followed soon after by Castiel. To the group's shock, they discover an actual ghost that begins killing people and the Winchesters and the Scooby Gang are forced to team up together to stop it. Working together, the Winchesters and the Scooby Gang trap the ghost who reveals himself to be a young boy who a greedy real estate developer in the real world is using to scare away reluctant shop owners. The ghost helps the Winchesters and Castiel fool the Scooby Gang into thinking that it was a human villain before returning the Winchesters and Castiel to the real world. There, the three put the ghost to rest and get the criminal arrested for tax evasion. Before getting sucked into Scooby-Doo, Castiel is shown to have gotten the fruit from the Tree of Life, bringing the Winchesters one step closer to their goal of opening a portal to Apocalypse World.

This episode is a crossover with Scooby-Doo.

281
17
"The Thing"
John Showalter
Davy Perez
April 5, 2018 (2018-04-05)
T13.20567
1.41[25]

Having gotten two of the needed ingredients to open a portal to Apocalypse World, the Winchesters search through the Men of Letters archive for clues on the Seal of Solomon. Finally, Dean discovers records showing that the Men of Letters found King Solomon's treasure in Israel in 1917, including the Seal, and stored it in their Portsmouth, Rhode Island chapter house. The Winchesters are able to locate the chapter house and find a young woman inside named Sandy Porter that has been trapped since 1925 and hasn't aged at all. Following an attack by a mysterious group, Sam learns that in 1925, a rouge Man of Letters named Diego Avila opened a rift into another dimension and brought forth the god Yokoth to cleanse the Earth. Sandy is in fact Yokoth who intends to bring her mate to Earth in Dean's body while the group that attacked are Men of Letters legacies who have been keeping Yokoth trapped. With the help of Diego's great-grandchildren, the Winchesters banish Yokoth back to her dimension and get the Seal of Solomon. At the same time, Arthur Ketch discovers Asmodeus using Gabriel's grace to power up. Asmodeus recognizes that Arthur seeks redemption and brutally beats him. In retaliation, Arthur rescues Gabriel and steals the archangel blade, bringing both to the Winchesters. Now having all the ingredients they need, the Winchesters open a door to Apocalypse World that will last twenty-four hours and Dean and Arthur pass through to finally rescue Jack and Mary.

282
18
"Bring 'em Back Alive"
Amyn Kaderali
Brad Buckner & Eugenie Ross-Leming
April 12, 2018 (2018-04-12)
T13.20568
1.53[26]

In Apocalypse World, Dean reluctantly works with Arthur Ketch to find Mary and Jack. To Dean's shock, he witnesses a group of angels holding the alternate reality version of his old friend Charlie Bradbury (Felicia Day) captive. Against Arthur's wishes, Dean launches a rescue mission for Charlie. Dean reveals that he still holds guilt over his Charlie's murder and Arthur agrees to help him. Together, the two men liberate Charlie who reveals that Mary and Jack are leading a resistance against Michael. Out of time before the rift closes, Dean returns to his Earth while Arthur remains behind in Apocalypse World to aid the resistance and coordinate for Dean's inevitable return with reinforcements. At the same time, Sam and Castiel attempt to help Gabriel, learning that he faked his death when Lucifer "killed" him in order to escape all responsibility again. Asmodeus eventually locates Gabriel and leads an attack on the bunker to recapture him. However, Gabriel recovers and kills Asmodeus. Gabriel chooses to abscond from his responsibility once again and departs, leaving the Winchesters without Gabriel's power to fight Michael or his grace to reopen the door to Apocalypse World. At the same time, Lucifer struggles in his new role as the ruler of Heaven, ultimately alienating Anael with his behavior.

283
19
"Funeralia"[27]
Nina Lopez-Corrado
Steve Yockey
April 19, 2018 (2018-04-19)
TBA
TBD

284
20
"Unfinished Business"[28]
Richard Speight, Jr.
Meredith Glynn
April 26, 2018 (2018-04-26)
TBA
TBD

285
21
"Beat the Devil"[29]
Phil Sgriccia
Robert Berens
May 3, 2018 (2018-05-03)
TBA
TBD

text: The twenty-third and final episode of the season will be written by Andrew Dabb, and directed by Robert Singer.[30]

text: Production[edit]

text: Supernatural was renewed for a thirteenth season by The CW on January 8, 2017.[31] This season is the first season not to feature Mark Sheppard as Crowley since his introduction in season 5, as the actor announced in May 2017 he would not be returning after his character was killed off for the last time.[32] Alexander Calvert, who was introduced as Jack in the twelfth season finale, was promoted to series regular for this season.[33]

text: Reception[edit]

text: The review aggregator website Rotten Tomatoes reports a 100% approval rating for Supernatural's thirteenth season, with an average rating of 7.87/10 based on 6 reviews.[34]

text: Ratings[edit]

text:
No.
Title
Air date
Rating/share
(18–49)
Viewers
(millions)
DVR
(18–49)
DVR viewers
(millions)
Total
(18–49)
Total viewers
(millions)

1
"Lost and Found"
October 12, 2017
0.7/3
2.10[9]
N/A
N/A
N/A
N/A

2
"The Rising Son"
October 19, 2017
0.7/3
1.90[10]
N/A
N/A
N/A
N/A

3
"Patience"
October 26, 2017
0.6/2
1.93[11]
N/A
N/A
N/A
N/A

4
"The Big Empty"
November 2, 2017
0.6/2
1.82[12]
0.5
N/A
1.1[35]
N/A

5
"Advanced Thanatology"
November 9, 2017
0.6/2
1.71[13]
N/A
N/A
N/A
N/A

6
"Tombstone"
November 16, 2017
0.7/3
1.89[14]
N/A
N/A
N/A
N/A

7
"War of the Worlds"
November 23, 2017
0.3/1
1.24[15]
0.5
1.21
0.8
2.45[36]

8
"The Scorpion and the Frog"
November 30, 2017
0.6/2
1.73[16]
N/A
N/A
N/A
N/A

9
"The Bad Place"
December 7, 2017
0.6/2
1.74[17]
N/A
N/A
N/A
N/A

10
"Wayward Sisters"
January 18, 2018
0.6/2
1.85[18]
0.4
N/A
1.0[37]
N/A

11
"Breakdown"
January 25, 2018
0.6/2
1.93[19]
0.5
1.10
1.1
3.03[38]

12
"Various & Sundry Villains"
February 1, 2018
0.6/2
1.68[20]
0.4
0.94
1.0
2.62[39]

13
"Devil's Bargain"
February 8, 2018
0.6/2
1.81[21]
0.4
1.08
1.0
2.89[40]

14
"Good Intentions"
March 1, 2018
0.6/2
1.61[22]
N/A
0.97
N/A
2.59[41]

15
"A Most Holy Man"
March 8, 2018
0.5/2
1.66[23]
0.4
1.05
0.9
2.73[42]

16
"Scoobynatural"
March 29, 2018
0.7/3
2.03[24]
0.6
1.32
1.3
3.36[43]

17
"The Thing"
April 5, 2018
0.4/2
1.41[25]
TBD
TBD
TBD
TBD

18
"Bring 'em Back Alive"
April 12, 2018
0.5/2
1.53[26]
TBD
TBD
TBD
TBD

19
"Funeralia"
April 19, 2018
TBD
TBD
TBD
TBD
TBD
TBD

20
"Unfinished Business"
April 26, 2018
TBD
TBD
TBD
TBD
TBD
TBD

21
"Beat the Devil"
May 3, 2018
TBD
TBD
TBD
TBD
TBD
TBD


document_title: Atom

question_text: what does the greek word for atoms mean

question_tokens: what does the greek word for atoms mean

root

text: Atom

text: History of atomic theory

text: Atoms in philosophy

text: The idea that matter is made up of discrete units is a very old idea, appearing in many ancient cultures such as Greece and India. The word "atom" (Greek: ἄτομος; atomos), meaning "uncuttable", was coined by the ancient Greek philosophers Leucippus and his pupil Democritus (c. 460 – c. 370 BC).[1][2][3][4] Democritus taught that atoms were infinite in number, uncreated, and eternal, and that the qualities of an object result from the kind of atoms that compose it.[2][3][4] Democritus's atomism was refined and elaborated by the later philosopher Epicurus (341 – 270 BC).[3][4] During the Early Middle Ages, atomism was mostly forgotten in western Europe, but survived among some groups of Islamic philosophers.[3] During the twelfth century, atomism became known again in western Europe through references to it in the newly-rediscovered writings of Aristotle.[3]

tag: p

text: In the fourteenth century, the rediscovery of major works describing atomist teachings, including Lucretius's De rerum natura and Diogenes Laërtius's Lives and Opinions of Eminent Philosophers, led to increased scholarly attention on the subject.[3] Nonetheless, because atomism was associated with the philosophy of Epicureanism, which contradicted orthodox Christian teachings, belief in atoms was not considered acceptable.[3] The French Catholic priest Pierre Gassendi (1592 – 1655) revived Epicurean atomism with modifications, arguing that atoms were created by God and, though extremely numerous, are not infinite.[3][4] Gassendi's modified theory of atoms was popularized in France by the physician François Bernier (1620 – 1688) and in England by the natural philosopher Walter Charleton (1619 – 1707).[3] The chemist Robert Boyle (1627 – 1691) and the physicist Isaac Newton (1642 – 1727) both defended atomism and, by the end of the seventeenth century, it had become accepted by portions of the scientific community.[3]

text: First evidence-based theory

text: In the early 1800s, John Dalton used the concept of atoms to explain why elements always react in ratios of small whole numbers (the law of multiple proportions). For instance, there are two types of tin oxide: one is 88.1% tin and 11.9% oxygen and the other is 78.7% tin and 21.3% oxygen (tin(II) oxide and tin dioxide respectively). This means that 100g of tin will combine either with 13.5g or 27g of oxygen. 13.5 and 27 form a ratio of 1:2, a ratio of small whole numbers. This common pattern in chemistry suggested to Dalton that elements react in multiples of discrete units — in other words, atoms. In the case of tin oxides, one tin atom will combine with either one or two oxygen atoms.[5]

text: Dalton also believed atomic theory could explain why water absorbs different gases in different proportions. For example, he found that water absorbs carbon dioxide far better than it absorbs nitrogen.[6] Dalton hypothesized this was due to the differences between the masses and configurations of the gases' respective particles, and carbon dioxide molecules (CO2) are heavier and larger than nitrogen molecules (N2).

text: Brownian motion

text: In 1827, botanist Robert Brown used a microscope to look at dust grains floating in water and discovered that they moved about erratically, a phenomenon that became known as "Brownian motion". This was thought to be caused by water molecules knocking the grains about. In 1905, Albert Einstein proved the reality of these molecules and their motions by producing the first statistical physics analysis of Brownian motion.[7][8][9] French physicist Jean Perrin used Einstein's work to experimentally determine the mass and dimensions of atoms, thereby conclusively verifying Dalton's atomic theory.[10]

text: Discovery of the electron

text: The physicist J. J. Thomson measured the mass of cathode rays, showing they were made of particles, but were around 1800 times lighter than the lightest atom, hydrogen. Therefore, they were not atoms, but a new particle, the first subatomic particle to be discovered, which he originally called "corpuscle" but was later named electron, after particles postulated by George Johnstone Stoney in 1874. He also showed they were identical to particles given off by photoelectric and radioactive materials.[11] It was quickly recognized that they are the particles that carry electric currents in metal wires, and carry the negative electric charge within atoms. Thomson was given the 1906 Nobel Prize in Physics for this work. Thus he overturned the belief that atoms are the indivisible, ultimate particles of matter.[12] Thomson also incorrectly postulated that the low mass, negatively charged electrons were distributed throughout the atom in a uniform sea of positive charge. This became known as the plum pudding model.

text: Discovery of the nucleus

text: In 1909, Hans Geiger and Ernest Marsden, under the direction of Ernest Rutherford, bombarded a metal foil with alpha particles to observe how they scattered. They expected all the alpha particles to pass straight through with little deflection, because Thomson's model said that the charges in the atom are so diffuse that their electric fields could not affect the alpha particles much. However, Geiger and Marsden spotted alpha particles being deflected by angles greater than 90°, which was supposed to be impossible according to Thomson's model. To explain this, Rutherford proposed that the positive charge of the atom is concentrated in a tiny nucleus at the center of the atom.[13]

text: Discovery of isotopes

text: While experimenting with the products of radioactive decay, in 1913 radiochemist Frederick Soddy discovered that there appeared to be more than one type of atom at each position on the periodic table.[14] The term isotope was coined by Margaret Todd as a suitable name for different atoms that belong to the same element. J. J. Thomson created a technique for isotope separation through his work on ionized gases, which subsequently led to the discovery of stable isotopes.[15]

text: Bohr model

text: In 1913 the physicist Niels Bohr proposed a model in which the electrons of an atom were assumed to orbit the nucleus but could only do so in a finite set of orbits, and could jump between these orbits only in discrete changes of energy corresponding to absorption or radiation of a photon.[16] This quantization was used to explain why the electrons orbits are stable (given that normally, charges in acceleration, including circular motion, lose kinetic energy which is emitted as electromagnetic radiation, see synchrotron radiation) and why elements absorb and emit electromagnetic radiation in discrete spectra.[17]

text: Later in the same year Henry Moseley provided additional experimental evidence in favor of Niels Bohr's theory. These results refined Ernest Rutherford's and Antonius Van den Broek's model, which proposed that the atom contains in its nucleus a number of positive nuclear charges that is equal to its (atomic) number in the periodic table. Until these experiments, atomic number was not known to be a physical and experimental quantity. That it is equal to the atomic nuclear charge remains the accepted atomic model today.[18]

text: Chemical bonding explained

text: Chemical bonds between atoms were now explained, by Gilbert Newton Lewis in 1916, as the interactions between their constituent electrons.[19] As the chemical properties of the elements were known to largely repeat themselves according to the periodic law,[20] in 1919 the American chemist Irving Langmuir suggested that this could be explained if the electrons in an atom were connected or clustered in some manner. Groups of electrons were thought to occupy a set of electron shells about the nucleus.[21]

text: Further developments in quantum physics

text: The Stern–Gerlach experiment of 1922 provided further evidence of the quantum nature of atomic properties. When a beam of silver atoms was passed through a specially shaped magnetic field, the beam was split in a way correlated with the direction of an atom's angular momentum, or spin. As this spin direction is initially random, the beam would be expected to deflect in a random direction. Instead, the beam was split into two directional components, corresponding to the atomic spin being oriented up or down with respect to the magnetic field.[22]

text: In 1925 Werner Heisenberg published the first consistent mathematical formulation of quantum mechanics (Matrix Mechanics).[18] One year earlier, in 1924, Louis de Broglie had proposed that all particles behave to an extent like waves and, in 1926, Erwin Schrödinger used this idea to develop a mathematical model of the atom (Wave Mechanics) that described the electrons as three-dimensional waveforms rather than point particles.

text:
A consequence of using waveforms to describe particles is that it is mathematically impossible to obtain precise values for both the position and momentum of a particle at a given point in time; this became known as the uncertainty principle, formulated by Werner Heisenberg in 1927.[18] In this concept, for a given accuracy in measuring a position one could only obtain a range of probable values for momentum, and vice versa.[23]
This model was able to explain observations of atomic behavior that previous models could not, such as certain structural and spectral patterns of atoms larger than hydrogen. Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.[24][25]

text: Discovery of the neutron

text: The development of the mass spectrometer allowed the mass of atoms to be measured with increased accuracy. The device uses a magnet to bend the trajectory of a beam of ions, and the amount of deflection is determined by the ratio of an atom's mass to its charge. The chemist Francis William Aston used this instrument to show that isotopes had different masses. The atomic mass of these isotopes varied by integer amounts, called the whole number rule.[26] The explanation for these different isotopes awaited the discovery of the neutron, an uncharged particle with a mass similar to the proton, by the physicist James Chadwick in 1932. Isotopes were then explained as elements with the same number of protons, but different numbers of neutrons within the nucleus.[27]

text: Fission, high-energy physics and condensed matter

text: In 1938, the German chemist Otto Hahn, a student of Rutherford, directed neutrons onto uranium atoms expecting to get transuranium elements. Instead, his chemical experiments showed barium as a product.[28][29] A year later, Lise Meitner and her nephew Otto Frisch verified that Hahn's result were the first experimental nuclear fission.[30][31] In 1944, Hahn received the Nobel prize in chemistry. Despite Hahn's efforts, the contributions of Meitner and Frisch were not recognized.[32]

text: In the 1950s, the development of improved particle accelerators and particle detectors allowed scientists to study the impacts of atoms moving at high energies.[33] Neutrons and protons were found to be hadrons, or composites of smaller particles called quarks. The standard model of particle physics was developed that so far has successfully explained the properties of the nucleus in terms of these sub-atomic particles and the forces that govern their interactions.[34]

text: Structure

text: Subatomic particles

text: Though the word atom originally denoted a particle that cannot be cut into smaller particles, in modern scientific usage the atom is composed of various subatomic particles. The constituent particles of an atom are the electron, the proton and the neutron; all three are fermions. However, the hydrogen-1 atom has no neutrons and the hydron ion has no electrons.

text: The electron is by far the least massive of these particles at 6969911000000000000♠9.11×10−31 kg, with a negative electrical charge and a size that is too small to be measured using available techniques.[35] It was the lightest particle with a positive rest mass measured, until the discovery of neutrino mass. Under ordinary conditions, electrons are bound to the positively charged nucleus by the attraction created from opposite electric charges. If an atom has more or fewer electrons than its atomic number, then it becomes respectively negatively or positively charged as a whole; a charged atom is called an ion. Electrons have been known since the late 19th century, mostly thanks to J.J. Thomson; see history of subatomic physics for details.

text: Protons have a positive charge and a mass 1,836 times that of the electron, at 6973167260000000000♠1.6726×10−27 kg. The number of protons in an atom is called its atomic number. Ernest Rutherford (1919) observed that nitrogen under alpha-particle bombardment ejects what appeared to be hydrogen nuclei. By 1920 he had accepted that the hydrogen nucleus is a distinct particle within the atom and named it proton.

text: Neutrons have no electrical charge and have a free mass of 1,839 times the mass of the electron,[36] or 6973169290000000000♠1.6929×10−27 kg, the heaviest of the three constituent particles, but it can be reduced by the nuclear binding energy. Neutrons and protons (collectively known as nucleons) have comparable dimensions—on the order of 6985250000000000000♠2.5×10−15 m—although the 'surface' of these particles is not sharply defined.[37] The neutron was discovered in 1932 by the English physicist James Chadwick.

text: In the Standard Model of physics, electrons are truly elementary particles with no internal structure. However, both protons and neutrons are composite particles composed of elementary particles called quarks. There are two types of quarks in atoms, each having a fractional electric charge. Protons are composed of two up quarks (each with charge +2/3) and one down quark (with a charge of −1/3). Neutrons consist of one up quark and two down quarks. This distinction accounts for the difference in mass and charge between the two particles.[38][39]

text: The quarks are held together by the strong interaction (or strong force), which is mediated by gluons. The protons and neutrons, in turn, are held to each other in the nucleus by the nuclear force, which is a residuum of the strong force that has somewhat different range-properties (see the article on the nuclear force for more). The gluon is a member of the family of gauge bosons, which are elementary particles that mediate physical forces.[38][39]

text: Nucleus

text: All the bound protons and neutrons in an atom make up a tiny atomic nucleus, and are collectively called nucleons. The radius of a nucleus is approximately equal to 1.07 3√A fm, where A is the total number of nucleons.[40] This is much smaller than the radius of the atom, which is on the order of 105 fm. The nucleons are bound together by a short-ranged attractive potential called the residual strong force. At distances smaller than 2.5 fm this force is much more powerful than the electrostatic force that causes positively charged protons to repel each other.[41]

text: Atoms of the same element have the same number of protons, called the atomic number. Within a single element, the number of neutrons may vary, determining the isotope of that element. The total number of protons and neutrons determine the nuclide. The number of neutrons relative to the protons determines the stability of the nucleus, with certain isotopes undergoing radioactive decay.[42]

text: The proton, the electron, and the neutron are classified as fermions. Fermions obey the Pauli exclusion principle which prohibits identical fermions, such as multiple protons, from occupying the same quantum state at the same time. Thus, every proton in the nucleus must occupy a quantum state different from all other protons, and the same applies to all neutrons of the nucleus and to all electrons of the electron cloud.[43]

text: A nucleus that has a different number of protons than neutrons can potentially drop to a lower energy state through a radioactive decay that causes the number of protons and neutrons to more closely match. As a result, atoms with matching numbers of protons and neutrons are more stable against decay. However, with increasing atomic number, the mutual repulsion of the protons requires an increasing proportion of neutrons to maintain the stability of the nucleus, which slightly modifies this trend of equal numbers of protons to neutrons.[43]

text: The number of protons and neutrons in the atomic nucleus can be modified, although this can require very high energies because of the strong force. Nuclear fusion occurs when multiple atomic particles join to form a heavier nucleus, such as through the energetic collision of two nuclei. For example, at the core of the Sun protons require energies of 3–10 keV to overcome their mutual repulsion—the coulomb barrier—and fuse together into a single nucleus.[44] Nuclear fission is the opposite process, causing a nucleus to split into two smaller nuclei—usually through radioactive decay. The nucleus can also be modified through bombardment by high energy subatomic particles or photons. If this modifies the number of protons in a nucleus, the atom changes to a different chemical element.[45][46]

text: If the mass of the nucleus following a fusion reaction is less than the sum of the masses of the separate particles, then the difference between these two values can be emitted as a type of usable energy (such as a gamma ray, or the kinetic energy of a beta particle), as described by Albert Einstein's mass–energy equivalence formula, E = mc2, where m is the mass loss and c is the speed of light. This deficit is part of the binding energy of the new nucleus, and it is the non-recoverable loss of the energy that causes the fused particles to remain together in a state that requires this energy to separate.[47]

text: The fusion of two nuclei that create larger nuclei with lower atomic numbers than iron and nickel—a total nucleon number of about 60—is usually an exothermic process that releases more energy than is required to bring them together.[48] It is this energy-releasing process that makes nuclear fusion in stars a self-sustaining reaction. For heavier nuclei, the binding energy per nucleon in the nucleus begins to decrease. That means fusion processes producing nuclei that have atomic numbers higher than about 26, and atomic masses higher than about 60, is an endothermic process. These more massive nuclei can not undergo an energy-producing fusion reaction that can sustain the hydrostatic equilibrium of a star.[43]

text: Electron cloud

text: The electrons in an atom are attracted to the protons in the nucleus by the electromagnetic force. This force binds the electrons inside an electrostatic potential well surrounding the smaller nucleus, which means that an external source of energy is needed for the electron to escape. The closer an electron is to the nucleus, the greater the attractive force. Hence electrons bound near the center of the potential well require more energy to escape than those at greater separations.

text: Electrons, like other particles, have properties of both a particle and a wave. The electron cloud is a region inside the potential well where each electron forms a type of three-dimensional standing wave—a wave form that does not move relative to the nucleus. This behavior is defined by an atomic orbital, a mathematical function that characterises the probability that an electron appears to be at a particular location when its position is measured.[49] Only a discrete (or quantized) set of these orbitals exist around the nucleus, as other possible wave patterns rapidly decay into a more stable form.[50] Orbitals can have one or more ring or node structures, and differ from each other in size, shape and orientation.[51]

text: Each atomic orbital corresponds to a particular energy level of the electron. The electron can change its state to a higher energy level by absorbing a photon with sufficient energy to boost it into the new quantum state. Likewise, through spontaneous emission, an electron in a higher energy state can drop to a lower energy state while radiating the excess energy as a photon. These characteristic energy values, defined by the differences in the energies of the quantum states, are responsible for atomic spectral lines.[50]

text: The amount of energy needed to remove or add an electron—the electron binding energy—is far less than the binding energy of nucleons. For example, it requires only 13.6 eV to strip a ground-state electron from a hydrogen atom,[52] compared to 2.23 million eV for splitting a deuterium nucleus.[53] Atoms are electrically neutral if they have an equal number of protons and electrons. Atoms that have either a deficit or a surplus of electrons are called ions. Electrons that are farthest from the nucleus may be transferred to other nearby atoms or shared between atoms. By this mechanism, atoms are able to bond into molecules and other types of chemical compounds like ionic and covalent network crystals.[54]

text: Properties

text: Nuclear properties

text: By definition, any two atoms with an identical number of protons in their nuclei belong to the same chemical element. Atoms with equal numbers of protons but a different number of neutrons are different isotopes of the same element. For example, all hydrogen atoms admit exactly one proton, but isotopes exist with no neutrons (hydrogen-1, by far the most common form,[55] also called protium), one neutron (deuterium), two neutrons (tritium) and more than two neutrons. The known elements form a set of atomic numbers, from the single proton element hydrogen up to the 118-proton element oganesson.[56] All known isotopes of elements with atomic numbers greater than 82 are radioactive, although the radioactivity of element 83 (bismuth) is so slight as to be practically negligible.[57][58]

text: About 339 nuclides occur naturally on Earth,[59] of which 254 (about 75%) have not been observed to decay, and are referred to as "stable isotopes". However, only 90 of these nuclides are stable to all decay, even in theory. Another 164 (bringing the total to 254) have not been observed to decay, even though in theory it is energetically possible. These are also formally classified as "stable". An additional 34 radioactive nuclides have half-lives longer than 80 million years, and are long-lived enough to be present from the birth of the solar system. This collection of 288 nuclides are known as primordial nuclides. Finally, an additional 51 short-lived nuclides are known to occur naturally, as daughter products of primordial nuclide decay (such as radium from uranium), or else as products of natural energetic processes on Earth, such as cosmic ray bombardment (for example, carbon-14).[60][note 1]

text: For 80 of the chemical elements, at least one stable isotope exists. As a rule, there is only a handful of stable isotopes for each of these elements, the average being 3.2 stable isotopes per element. Twenty-six elements have only a single stable isotope, while the largest number of stable isotopes observed for any element is ten, for the element tin. Elements 43, 61, and all elements numbered 83 or higher have no stable isotopes.[61][page needed]

text: Stability of isotopes is affected by the ratio of protons to neutrons, and also by the presence of certain "magic numbers" of neutrons or protons that represent closed and filled quantum shells. These quantum shells correspond to a set of energy levels within the shell model of the nucleus; filled shells, such as the filled shell of 50 protons for tin, confers unusual stability on the nuclide. Of the 254 known stable nuclides, only four have both an odd number of protons and odd number of neutrons: hydrogen-2 (deuterium), lithium-6, boron-10 and nitrogen-14. Also, only four naturally occurring, radioactive odd–odd nuclides have a half-life over a billion years: potassium-40, vanadium-50, lanthanum-138 and tantalum-180m. Most odd–odd nuclei are highly unstable with respect to beta decay, because the decay products are even–even, and are therefore more strongly bound, due to nuclear pairing effects.[61][page needed]

text: Mass

text: The large majority of an atom's mass comes from the protons and neutrons that make it up. The total number of these particles (called "nucleons") in a given atom is called the mass number. It is a positive integer and dimensionless (instead of having dimension of mass), because it expresses a count. An example of use of a mass number is "carbon-12," which has 12 nucleons (six protons and six neutrons).

text: The actual mass of an atom at rest is often expressed using the unified atomic mass unit (u), also called dalton (Da). This unit is defined as a twelfth of the mass of a free neutral atom of carbon-12, which is approximately 6973166000000000000♠1.66×10−27 kg.[62] Hydrogen-1 (the lightest isotope of hydrogen which is also the nuclide with the lowest mass) has an atomic weight of 1.007825 u.[63] The value of this number is called the atomic mass. A given atom has an atomic mass approximately equal (within 1%) to its mass number times the atomic mass unit (for example the mass of a nitrogen-14 is roughly 14 u). However, this number will not be exactly an integer except in the case of carbon-12 (see below).[64] The heaviest stable atom is lead-208,[57] with a mass of 7002207976652100000♠207.9766521 u.[65]

text: As even the most massive atoms are far too light to work with directly, chemists instead use the unit of moles. One mole of atoms of any element always has the same number of atoms (about 7023602200000000000♠6.022×1023). This number was chosen so that if an element has an atomic mass of 1 u, a mole of atoms of that element has a mass close to one gram. Because of the definition of the unified atomic mass unit, each carbon-12 atom has an atomic mass of exactly 12 u, and so a mole of carbon-12 atoms weighs exactly 0.012 kg.[62]

text: Shape and size

text: Atoms lack a well-defined outer boundary, so their dimensions are usually described in terms of an atomic radius. This is a measure of the distance out to which the electron cloud extends from the nucleus.[66] However, this assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. Atomic radii may be derived from the distances between two nuclei when the two atoms are joined in a chemical bond. The radius varies with the location of an atom on the atomic chart, the type of chemical bond, the number of neighboring atoms (coordination number) and a quantum mechanical property known as spin.[67] On the periodic table of the elements, atom size tends to increase when moving down columns, but decrease when moving across rows (left to right).[68] Consequently, the smallest atom is helium with a radius of 32 pm, while one of the largest is caesium at 225 pm.[69]

text: When subjected to external forces, like electrical fields, the shape of an atom may deviate from spherical symmetry. The deformation depends on the field magnitude and the orbital type of outer shell electrons, as shown by group-theoretical considerations. Aspherical deviations might be elicited for instance in crystals, where large crystal-electrical fields may occur at low-symmetry lattice sites.[70][71] Significant ellipsoidal deformations have been shown to occur for sulfur ions[72] and chalcogen ions[73] in pyrite-type compounds.

text: Atomic dimensions are thousands of times smaller than the wavelengths of light (400–700 nm) so they cannot be viewed using an optical microscope. However, individual atoms can be observed using a scanning tunneling microscope. To visualize the minuteness of the atom, consider that a typical human hair is about 1 million carbon atoms in width.[74] A single drop of water contains about 2 sextillion (7021200000000000000♠2×1021) atoms of oxygen, and twice the number of hydrogen atoms.[75] A single carat diamond with a mass of 6996200000000000000♠2×10−4 kg contains about 10 sextillion (1022) atoms of carbon.[note 2] If an apple were magnified to the size of the Earth, then the atoms in the apple would be approximately the size of the original apple.[76]

text: Radioactive decay

text: Every element has one or more isotopes that have unstable nuclei that are subject to radioactive decay, causing the nucleus to emit particles or electromagnetic radiation. Radioactivity can occur when the radius of a nucleus is large compared with the radius of the strong force, which only acts over distances on the order of 1 fm.[77]

text: The most common forms of radioactive decay are:[78][79]

text:
Alpha decay: this process is caused when the nucleus emits an alpha particle, which is a helium nucleus consisting of two protons and two neutrons. The result of the emission is a new element with a lower atomic number.
Beta decay (and electron capture): these processes are regulated by the weak force, and result from a transformation of a neutron into a proton, or a proton into a neutron. The neutron to proton transition is accompanied by the emission of an electron and an antineutrino, while proton to neutron transition (except in electron capture) causes the emission of a positron and a neutrino. The electron or positron emissions are called beta particles. Beta decay either increases or decreases the atomic number of the nucleus by one. Electron capture is more common than positron emission, because it requires less energy. In this type of decay, an electron is absorbed by the nucleus, rather than a positron emitted from the nucleus. A neutrino is still emitted in this process, and a proton changes to a neutron.
Gamma decay: this process results from a change in the energy level of the nucleus to a lower state, resulting in the emission of electromagnetic radiation. The excited state of a nucleus which results in gamma emission usually occurs following the emission of an alpha or a beta particle. Thus, gamma decay usually follows alpha or beta decay.

tag: ul

text: Other more rare types of radioactive decay include ejection of neutrons or protons or clusters of nucleons from a nucleus, or more than one beta particle. An analog of gamma emission which allows excited nuclei to lose energy in a different way, is internal conversion—a process that produces high-speed electrons that are not beta rays, followed by production of high-energy photons that are not gamma rays. A few large nuclei explode into two or more charged fragments of varying masses plus several neutrons, in a decay called spontaneous nuclear fission.

text: Each radioactive isotope has a characteristic decay time period—the half-life—that is determined by the amount of time needed for half of a sample to decay. This is an exponential decay process that steadily decreases the proportion of the remaining isotope by 50% every half-life. Hence after two half-lives have passed only 25% of the isotope is present, and so forth.[77]

text: Magnetic moment

text: Elementary particles possess an intrinsic quantum mechanical property known as spin. This is analogous to the angular momentum of an object that is spinning around its center of mass, although strictly speaking these particles are believed to be point-like and cannot be said to be rotating. Spin is measured in units of the reduced Planck constant (ħ), with electrons, protons and neutrons all having spin ½ ħ, or "spin-½". In an atom, electrons in motion around the nucleus possess orbital angular momentum in addition to their spin, while the nucleus itself possesses angular momentum due to its nuclear spin.[80]

text: The magnetic field produced by an atom—its magnetic moment—is determined by these various forms of angular momentum, just as a rotating charged object classically produces a magnetic field. However, the most dominant contribution comes from electron spin. Due to the nature of electrons to obey the Pauli exclusion principle, in which no two electrons may be found in the same quantum state, bound electrons pair up with each other, with one member of each pair in a spin up state and the other in the opposite, spin down state. Thus these spins cancel each other out, reducing the total magnetic dipole moment to zero in some atoms with even number of electrons.[81]

text: In ferromagnetic elements such as iron, cobalt and nickel, an odd number of electrons leads to an unpaired electron and a net overall magnetic moment. The orbitals of neighboring atoms overlap and a lower energy state is achieved when the spins of unpaired electrons are aligned with each other, a spontaneous process known as an exchange interaction. When the magnetic moments of ferromagnetic atoms are lined up, the material can produce a measurable macroscopic field. Paramagnetic materials have atoms with magnetic moments that line up in random directions when no magnetic field is present, but the magnetic moments of the individual atoms line up in the presence of a field.[81][82]

text: The nucleus of an atom will have no spin when it has even numbers of both neutrons and protons, but for other cases of odd numbers, the nucleus may have a spin. Normally nuclei with spin are aligned in random directions because of thermal equilibrium. However, for certain elements (such as xenon-129) it is possible to polarize a significant proportion of the nuclear spin states so that they are aligned in the same direction—a condition called hyperpolarization. This has important applications in magnetic resonance imaging.[83][84]

text: Energy levels

text: The potential energy of an electron in an atom is negative, its dependence of its position reaches the minimum (the most absolute value) inside the nucleus, and vanishes when the distance from the nucleus goes to infinity, roughly in an inverse proportion to the distance. In the quantum-mechanical model, a bound electron can only occupy a set of states centered on the nucleus, and each state corresponds to a specific energy level; see time-independent Schrödinger equation for theoretical explanation. An energy level can be measured by the amount of energy needed to unbind the electron from the atom, and is usually given in units of electronvolts (eV). The lowest energy state of a bound electron is called the ground state, i.e. stationary state, while an electron transition to a higher level results in an excited state.[85] The electron's energy raises when n increases because the (average) distance to the nucleus increases. Dependence of the energy on ℓ is caused not by electrostatic potential of the nucleus, but by interaction between electrons.

text:
For an electron to transition between two different states, e.g. grounded state to first excited level (ionization), it must absorb or emit a photon at an energy matching the difference in the potential energy of those levels, according to Niels Bohr model, what can be precisely calculated by the Schrödinger equation.
Electrons jump between orbitals in a particle-like fashion. For example, if a single photon strikes the electrons, only a single electron changes states in response to the photon; see Electron properties.

text: The energy of an emitted photon is proportional to its frequency, so these specific energy levels appear as distinct bands in the electromagnetic spectrum.[86] Each element has a characteristic spectrum that can depend on the nuclear charge, subshells filled by electrons, the electromagnetic interactions between the electrons and other factors.[87]

text: When a continuous spectrum of energy is passed through a gas or plasma, some of the photons are absorbed by atoms, causing electrons to change their energy level. Those excited electrons that remain bound to their atom spontaneously emit this energy as a photon, traveling in a random direction, and so drop back to lower energy levels. Thus the atoms behave like a filter that forms a series of dark absorption bands in the energy output. (An observer viewing the atoms from a view that does not include the continuous spectrum in the background, instead sees a series of emission lines from the photons emitted by the atoms.) Spectroscopic measurements of the strength and width of atomic spectral lines allow the composition and physical properties of a substance to be determined.[88]

text: Close examination of the spectral lines reveals that some display a fine structure splitting. This occurs because of spin–orbit coupling, which is an interaction between the spin and motion of the outermost electron.[89] When an atom is in an external magnetic field, spectral lines become split into three or more components; a phenomenon called the Zeeman effect. This is caused by the interaction of the magnetic field with the magnetic moment of the atom and its electrons. Some atoms can have multiple electron configurations with the same energy level, which thus appear as a single spectral line. The interaction of the magnetic field with the atom shifts these electron configurations to slightly different energy levels, resulting in multiple spectral lines.[90] The presence of an external electric field can cause a comparable splitting and shifting of spectral lines by modifying the electron energy levels, a phenomenon called the Stark effect.[91]

text: If a bound electron is in an excited state, an interacting photon with the proper energy can cause stimulated emission of a photon with a matching energy level. For this to occur, the electron must drop to a lower energy state that has an energy difference matching the energy of the interacting photon. The emitted photon and the interacting photon then move off in parallel and with matching phases. That is, the wave patterns of the two photons are synchronized. This physical property is used to make lasers, which can emit a coherent beam of light energy in a narrow frequency band.[92]

text: Valence and bonding behavior

text:
Valency is the combining power of an element. It is equal to number of hydrogen atoms that atom can combine or displace in forming compounds.[93] The outermost electron shell of an atom in its uncombined state is known as the valence shell, and the electrons in
that shell are called valence electrons. The number of valence electrons determines the bonding
behavior with other atoms. Atoms tend to chemically react with each other in a manner that fills (or empties) their outer valence shells.[94] For example, a transfer of a single electron between atoms is a useful approximation for bonds that form between atoms with one-electron more than a filled shell, and others that are one-electron short of a full shell, such as occurs in the compound sodium chloride and other chemical ionic salts. However, many elements display multiple valences, or tendencies to share differing numbers of electrons in different compounds. Thus, chemical bonding between these elements takes many forms of electron-sharing that are more than simple electron transfers. Examples include the element carbon and the organic compounds.[95]

text: The chemical elements are often displayed in a periodic table that is laid out to display recurring chemical properties, and elements with the same number of valence electrons form a group that is aligned in the same column of the table. (The horizontal rows correspond to the filling of a quantum shell of electrons.) The elements at the far right of the table have their outer shell completely filled with electrons, which results in chemically inert elements known as the noble gases.[96][97]

text: States

text: Quantities of atoms are found in different states of matter that depend on the physical conditions, such as temperature and pressure. By varying the conditions, materials can transition between solids, liquids, gases and plasmas.[98] Within a state, a material can also exist in different allotropes. An example of this is solid carbon, which can exist as graphite or diamond.[99] Gaseous allotropes exist as well, such as dioxygen and ozone.

text:
At temperatures close to absolute zero, atoms can form a Bose–Einstein condensate, at which point quantum mechanical effects, which are normally only observed at the atomic scale, become apparent on a macroscopic scale.[100][101] This super-cooled collection of atoms
then behaves as a single super atom, which may allow fundamental checks of quantum mechanical behavior.[102]

text: Identification

text: The scanning tunneling microscope is a device for viewing surfaces at the atomic level. It uses the quantum tunneling phenomenon, which allows particles to pass through a barrier that would normally be insurmountable. Electrons tunnel through the vacuum between two planar metal electrodes, on each of which is an adsorbed atom, providing a tunneling-current density that can be measured. Scanning one atom (taken as the tip) as it moves past the other (the sample) permits plotting of tip displacement versus lateral separation for a constant current. The calculation shows the extent to which scanning-tunneling-microscope images of an individual atom are visible. It confirms that for low bias, the microscope images the space-averaged dimensions of the electron orbitals across closely packed energy levels—the Fermi level local density of states.[103][104]

text: An atom can be ionized by removing one of its electrons. The electric charge causes the trajectory of an atom to bend when it passes through a magnetic field. The radius by which the trajectory of a moving ion is turned by the magnetic field is determined by the mass of the atom. The mass spectrometer uses this principle to measure the mass-to-charge ratio of ions. If a sample contains multiple isotopes, the mass spectrometer can determine the proportion of each isotope in the sample by measuring the intensity of the different beams of ions. Techniques to vaporize atoms include inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry, both of which use a plasma to vaporize samples for analysis.[105]

text: A more area-selective method is electron energy loss spectroscopy, which measures the energy loss of an electron beam within a transmission electron microscope when it interacts with a portion of a sample. The atom-probe tomograph has sub-nanometer resolution in 3-D and can chemically identify individual atoms using time-of-flight mass spectrometry.[106]

text: Spectra of excited states can be used to analyze the atomic composition of distant stars. Specific light wavelengths contained in the observed light from stars can be separated out and related to the quantized transitions in free gas atoms. These colors can be replicated using a gas-discharge lamp containing the same element.[107] Helium was discovered in this way in the spectrum of the Sun 23 years before it was found on Earth.[108]

text: Origin and current state

text: Atoms form about 4% of the total energy density of the observable Universe, with an average density of about 0.25 atoms/m3.[109] Within a galaxy such as the Milky Way, atoms have a much higher concentration, with the density of matter in the interstellar medium (ISM) ranging from 105 to 109 atoms/m3.[110] The Sun is believed to be inside the Local Bubble, a region of highly ionized gas, so the density in the solar neighborhood is only about 103 atoms/m3.[111] Stars form from dense clouds in the ISM, and the evolutionary processes of stars result in the steady enrichment of the ISM with elements more massive than hydrogen and helium. Up to 95% of the Milky Way's atoms are concentrated inside stars and the total mass of atoms forms about 10% of the mass of the galaxy.[112] (The remainder of the mass is an unknown dark matter.)[113]

text: Formation

text: Electrons are thought to exist in the Universe since early stages of the Big Bang. Atomic nuclei forms in nucleosynthesis reactions. In about three minutes Big Bang nucleosynthesis produced most of the helium, lithium, and deuterium in the Universe, and perhaps some of the beryllium and boron.[114][115][116]

text: Ubiquitousness and stability of atoms relies on their binding energy, which means that an atom has a lower energy than an unbound system of the nucleus and electrons. Where the temperature is much higher than ionization potential, the matter exists in the form of plasma—a gas of positively charged ions (possibly, bare nuclei) and electrons. When the temperature drops below the ionization potential, atoms become statistically favorable. Atoms (complete with bound electrons) became to dominate over charged particles 380,000 years after the Big Bang—an epoch called recombination, when the expanding Universe cooled enough to allow electrons to become attached to nuclei.[117]

text: Since the Big Bang, which produced no carbon or heavier elements, atomic nuclei have been combined in stars through the process of nuclear fusion to produce more of the element helium, and (via the triple alpha process) the sequence of elements from carbon up to iron;[118] see stellar nucleosynthesis for details.

text: Isotopes such as lithium-6, as well as some beryllium and boron are generated in space through cosmic ray spallation.[119] This occurs when a high-energy proton strikes an atomic nucleus, causing large numbers of nucleons to be ejected.

text: Elements heavier than iron were produced in supernovae through the r-process and in AGB stars through the s-process, both of which involve the capture of neutrons by atomic nuclei.[120] Elements such as lead formed largely through the radioactive decay of heavier elements.[121]

text: Earth

text: Most of the atoms that make up the Earth and its inhabitants were present in their current form in the nebula that collapsed out of a molecular cloud to form the Solar System. The rest are the result of radioactive decay, and their relative proportion can be used to determine the age of the Earth through radiometric dating.[122][123] Most of the helium in the crust of the Earth (about 99% of the helium from gas wells, as shown by its lower abundance of helium-3) is a product of alpha decay.[124]

text: There are a few trace atoms on Earth that were not present at the beginning (i.e., not "primordial"), nor are results of radioactive decay. Carbon-14 is continuously generated by cosmic rays in the atmosphere.[125] Some atoms on Earth have been artificially generated either deliberately or as by-products of nuclear reactors or explosions.[126][127] Of the transuranic elements—those with atomic numbers greater than 92—only plutonium and neptunium occur naturally on Earth.[128][129] Transuranic elements have radioactive lifetimes shorter than the current age of the Earth[130] and thus identifiable quantities of these elements have long since decayed, with the exception of traces of plutonium-244 possibly deposited by cosmic dust.[122] Natural deposits of plutonium and neptunium are produced by neutron capture in uranium ore.[131]

text: The Earth contains approximately 7050133000000000000♠1.33×1050 atoms.[132] Although small numbers of independent atoms of noble gases exist, such as argon, neon, and helium, 99% of the atmosphere is bound in the form of molecules, including carbon dioxide and diatomic oxygen and nitrogen. At the surface of the Earth, an overwhelming majority of atoms combine to form various compounds, including water, salt, silicates and oxides. Atoms can also combine to create materials that do not consist of discrete molecules, including crystals and liquid or solid metals.[133][134] This atomic matter forms networked arrangements that lack the particular type of small-scale interrupted order associated with molecular matter.[135]

text: Rare and theoretical forms

text: Superheavy elements

text: While isotopes with atomic numbers higher than lead (82) are known to be radioactive, an "island of stability" has been proposed for some elements with atomic numbers above 103. These superheavy elements may have a nucleus that is relatively stable against radioactive decay.[136] The most likely candidate for a stable superheavy atom, unbihexium, has 126 protons and 184 neutrons.[137]

text: Exotic matter

text: Each particle of matter has a corresponding antimatter particle with the opposite electrical charge. Thus, the positron is a positively charged antielectron and the antiproton is a negatively charged equivalent of a proton. When a matter and corresponding antimatter particle meet, they annihilate each other. Because of this, along with an imbalance between the number of matter and antimatter particles, the latter are rare in the universe. The first causes of this imbalance are not yet fully understood, although theories of baryogenesis may offer an explanation. As a result, no antimatter atoms have been discovered in nature.[138][139] However, in 1996 the antimatter counterpart of the hydrogen atom (antihydrogen) was synthesized at the CERN laboratory in Geneva.[140][141]

text: Other exotic atoms have been created by replacing one of the protons, neutrons or electrons with other particles that have the same charge. For example, an electron can be replaced by a more massive muon, forming a muonic atom. These types of atoms can be used to test the fundamental predictions of physics.[142][143][144]


document_title: List of the longest-running West End shows

question_text: longest running play in london's west end

question_tokens: longest running play in london 's west end

text: List[edit]

text: Unless otherwise states, the number of performances listed is for the original West End production of the show.  M denotes a musical, P denotes a straight play, R denotes a revue, D denotes a dance musical, and S denotes a special case.  An asterisk indicates an announced closing date for a currently-running show.  All currently-running shows are updated as of 8 January 2018, unless otherwise stated.

text:
#

Title

Genre

Openingdate

Closingdate

Performances

Comment

1

The Mousetrap

P

25 November 1952

27,174

Currently running at the St. Martin's Theatre
6 October 1952 – Production premiere at the Theatre Royal, Nottingham
25 November 1952 – Opened in the West End at the New Ambassadors Theatre
13 September 1957 – Longest-running West End play
12 April 1958 – Longest-running West End show overall, 2239 performances
9 December 1964 – 5,000 performances
23 March 1974 – Closed for 2 days to transfer to the St. Martin's Theatre, retaining initial run status
17 December 1976 – 10,000 performances
16 December 2000 – 20,000 performances
18 November 2012 - 25,000 performances
1965 & 1999 – Sets, costumes and props replaced

2

Les Misérables

M

8 October 1985

13,341

Currently running at the Queen's Theatre
Opened at the Royal Shakespeare Company's Barbican Theatre.
Transferred to the Palace Theatre on the West End on 5 December 1985.
Transferred to the Queen's Theatre in April 2004, where it is still running.

3

The Phantom of the Opera

M

9 October 1986

13,008

Currently running at Her Majesty's Theatre

4

The Woman in Black

P

7 June 1989

11,704

Currently running at Fortune Theatre

5

Blood Brothers

M

28 July 1988

10 November 2012

10,013

6

Cats

M

11 May 1981

11 May 2002

8,949

Opened in London at the New London Theatre
The show closed on its 21st anniversary, where it was broadcast in Covent Garden for those who couldn't acquire a ticket
It held the record for longest running West End Musical for four years before it was overtaken by Les Misérables, the current record holder.

7

Mamma Mia!

M

6 April 1999

7,871

Currently running at Novello Theatre
This is the longest running jukebox musical
Opened at the Prince Edward Theatre
Moved to the Prince of Wales Theatre on 9 June 2004
Moved to Novello Theatre in September 2012

8

The Lion King

M

19 October 1999

7,634

Currently running at Lyceum Theatre

9

Starlight Express

M

27 March 1984

12 January 2002

7,406

10

No Sex Please, We're British

P

3 June 1971

16 January 1987

6,761

11

Stomp

D

25 September 2002

7 January 2018

6,512

Opened at the Vaudeville Theatre
Moved to the Ambassadors Theatre on 27 September 2007

12

Chicago

M

18 October 1997

1 September 2012

6,187

This is the longest running revival
Show opened at the Adelphi Theatre
Moved to the Cambridge Theatre in April 2006
Moved to the Garrick Theatre in November 2011

13

Buddy – The Buddy Holly Story

M

12 October 1989

3 March 2002

5,140

Opened at the Victoria Palace Theatre
Moved to the Strand Theatre (now the Novello Theatre) in October 1995

14

Wicked

M

27 September 2006

4,746

Currently running at Apollo Victoria Theatre

15

We Will Rock You

M

25 September 2002

31 May 2014

4,659

16

Billy Elliot the Musical

M

11 May 2005

9 April 2016

4,566

17

Miss Saigon

M

20 September 1989

30 October 1999

4,264

18

Jersey Boys

M

18 March 2008

26 March 2017

3,787

19

Thriller - Live

R

26 January 2009

3,745

Currently running at Lyric Theatre

20

The Complete Works of William Shakespeare (Abridged)

P

7 March 1996

3 April 2005

3,744

21

The 39 Steps

P

14 September 2006

5 September 2015

3,731 [note 1]

22

Jesus Christ Superstar

M

9 August 1972

23 August 1980

3,357

23

Me and My Girl

M

12 February 1985

16 January 1993

3,303

This is a revival of the 1937 musical.

24

Evita

M

21 June 1978

18 February 1986

3,176 [note 2]

tag: table

text: Oh! Calcutta! which opened in the West End on 30 September 1970 and closed in either January or February 1980, would have approximately 3,800 performances, but no closing date is known, so proper ranking cannot be made.[note 3]

text: The next longest running play is There's a Girl in My Soup (1966–1973). The next longest running musical is Oliver! (1960–1966).


document_title: Sitting on the fence

question_text: what is the meaning of the idiom sit on the fence

text: Sitting on the fence

text: "Sitting on the fence" is a common idiom used in English to describe one's neutrality or hesitance to choose between two sides in an argument or a competition, or inability to decide due to lack of courage.[1] This is done either in order to remain on good terms with both sides, or due to apathy regarding the situation and not wanting to choose a position with which one doesn't actually agree.[2] As a result, someone who "sits on the fence" will maintain a neutral and non-committal view regarding any of the other parties involved.


document_title: Lookout Mountain

question_text: where in tennessee can you see 7 states

question_tokens: where in tennessee can you see 7 states

text: Lookout Mountain

text: Name[edit]

text: The name Lookout Mountain is said to have come from General Andrew Jackson's troops, but more likely comes from the Cherokee term for "two mountains looking at each other".[3]

text: Geography[edit]

text: Northern and eastern slopes and summit[edit]

text: Lookout Mountain and Sand Mountain (to the southwest) make up a large portion of the southernmost end of the Cumberland Plateau. The area was lifted from an ancient sea, and worn down by erosion for millions of years. The summit, called "High Point", is located just east of Thompsonville in Walker County, Georgia, with an elevation of 2,392 feet (729 m) above sea level. The foothills of the mountain extend into Chickamauga and Chattanooga National Military Park.

text: The caves of Ruby Falls are in Lookout Mountain, and the rock formations of the "City of Rocks" (or Rock City) attraction are situated on the ridge. The area is home to the Lookout Mountain Incline Railway, Covenant College, and a hang-gliding school. Lookout Mountain is one of the Chattanooga area's most visited tourist attractions. Civil War-related landmarks include "Point Park", operated by the National Park Service, and the Cravens House. Nearby are Georgia's Cloudland Canyon and Cloudland Canyon State Park.[citation needed]

text: Southern and western slopes[edit]

text: The southwestern section of Lookout Mountain is in Alabama. The Little River, in Little River Canyon on the mountain, is the only river that begins and ends entirely on top of a mountain.[citation needed] The river flows over the DeSoto Falls in DeSoto State Park. The Noccalula Falls Park, featuring a pioneer village showcasing several nineteenth-century homes, is located at the southern terminus of Lookout Mountain, near Gadsden, Alabama. Local legend claims that the 90-foot falls' namesake, Noccalula, jumped to her death because she could not marry the man she loved.[citation needed]

text: White water sports and rock-climbing (offering views of the Coosa River Basin) are this area's key attractions.

text: Seven states[edit]

text: From the "Rock City" point, a marker claims that seven U.S. states could be seen: Tennessee, Kentucky, Virginia, South Carolina, North Carolina, Georgia, and Alabama. The claim is repeated on numerous barn roofs in the surrounding area. No scientific investigation has upheld this claim.[4]

text: Sunset Rock[edit]

text: Located on the northwest side of Lookout Mountain, Sunset Rock is a popular trailhead and tourist stop. It is part of the Chickamauga and Chattanooga Military State Park, the largest and oldest Civil War national park.[5][6] Once known as Point Lookout, Sunset Rock provides a view of the Tennessee River, Signal Mountain and Prentice Cooper State Forest.[7][8] The 100-foot cliff and moderate temperatures invite heavy traffic for its many climbing routes, which were completed in 1960. Sunset Rock is mainly sandstone; making for easier routing and climbing. Route development continued through the 1960s and 1970s. In the 1980s, routers pushed the grades ever higher. Climbing here is especially popular in the autumn months due to cooler weather.[9]

text: Sunset Rock is attractive to Civil War enthusiasts due to its history; it has a Tennessee Historical Commission Marker at the head of the trail, describing its Civil War battle history. Confederate Generals Braxton Bragg and James Longstreet [10] used Sunset Rock as a lookout in 1863 where they were able to track the movement of the Union troops as they entered Lookout Valley. It is claimed that unknown to Longstreet, the Union troops could see him on Sunset Rock from the valley, where they were able to decipher the Confederate code, giving them the ability to anticipate the next moves of the Confederates.[11] This resulted in the Battle of Wauhatchie, in which the Confederate army attempted to remove the Union forces from the river and block their supply lines. The attempt was unsuccessful; with the consequence that the Union forces were able to lay siege to Chattanooga.

text: History[edit]

text: Native Americans and Lookout Mountain[edit]

text: A branch of Cherokee Native Americans lived in Chattanooga, the Chickamauga people. The Chickamauga called the mountain Chat-a-nu-ga; hence the name of the city. Research suggests the mountain was inhabited, although no physical evidence has been found. On top of the mountain, the pattern of boulders suggest lanes or walls were once there.[12]

text: Revolutionary War and aftermath[edit]

text: Legend has it that during the Revolutionary War, a battle, between the forces of John Sevier and those of Chief Dragging Canoe of the Chickamauga Cherokee, took place on Lookout Mountain. Archaeologist and ethno-historian, Raymond Evans, has asserted that such a battle could not have taken place.[13] However, a battle between Sevier's militia forces from the State of Franklin and those of Dragging Canoe did occur there in August 1788.[14]

text: Settlements[edit]

text: It was reported that on August 28, 1823, Daniel S. Butrick and William Chamberlain arrived at Lookout Mountain to perform missionary work with Native Americans.[citation needed] After the Trail of Tears, land taken from the tribes was purchased by the highest bidder without a lottery of land parcels. This method of distributing land caused much of Lookout Mountain to be owned by a few wealthy Chattanooga families.[citation needed]

text: The aptly named Summertown, located on top of the mountain, was barely accessible from a small rutted turnpike which had been built in 1852 by Colonel James A. Whiteside. Whiteside, a native of Danville, Kentucky, owned a summer home which he converted into a hotel with several cottages. Naturalists who came to the area and visited the summit, such as Bradford Torrey, thought the cottages spoiled the environment and made it look like a cheap resort. Whiteside had purchased much of the land on the mountain's summit.[citation needed] Another wealthy Chattanoogan, Robert Cravens, had purchased most of the land on the side of the mountain. Cravens was also instrumental in developing the area, and moved into the house he built (the Cravens House) in 1855. Within a few years, about 25 families regularly summered on the mountain.[citation needed]

text: Lookout Mountain's Sunset Rock was once the home to the photo shop of JB Linn.[15] After the Union forces under Major General Joseph Hooker took over the mountain, Linn gained access to Sunset Rock (then called Point Lookout). He built a small shack there and named it "Gallery Point Lookout".[citation needed] In December 1863, he and his brother began taking photographs of many war commanders and officers, as well as wealthy civilians in the area. They became very successful with these pictures. The Gallery Point Lookout House is no longer in existence, but many of Linn's photographs still exist.

text: Civil War[edit]

text: On November 24, 1863, the Battle of Lookout Mountain was fought on the slopes of the mountain. The majority of hand-to-hand combat took place near Cravens' house (about halfway to the summit). Lookout Mountain's shape and location can in some conditions cause a unique weather phenomenon in the area: after dawn, fog will sometimes descend from the cooler mountaintop and stop about halfway down. Such an event took place the day of the battle and is the reason for its romanticized name, the "Battle Above the Clouds." The battle was won by Union forces, enabling them to lift the Confederate siege of Chattanooga.[citation needed]

text: Post Civil War[edit]

text: Yellow Fever Epidemic[edit]

text: When cases of Yellow fever began to increase in the United States, the Chattanooga population believed that the city was immune to any possibility of an epidemic because of its mountain climate. In 1878, the death of two individuals from the disease encouraged a widespread panic, causing an estimated 12,000 individuals to leave the city. A large percentage of this group went up the mountain, believing the climate would offer some protection against the disease. After the epidemic passed, many people complained about the inconvenient and complicated travel up the mountain, and the St. Elmo Turnpike (Ochs Highway) was created to help with access to the mountain.[16] Early in the 1900s, Lookout Mountain was incorporated as a town.

text: Twentieth century tourist boom[edit]

text: Entrepreneurs began marketing their own attractions in the 1910s and 1920s. Instead of serving just as a resort area for the wealthy, rich businessmen settled permanently on the mountain. Garnet Carter, J. B. Pound, O. B. Andrews, and Leo Lambert were a few of the more successful entrepreneurs who created their own attractions. Instead of making their money off of the tourist's room, board, or transportation, the area's natural attractions were enhanced. Sites that had long been popular (such as the 'City of Rocks", Lookout Mountain Cave –closed to the public since 1935– and the Lookout Mountain Incline Railway), were bought, "highly developed", and marketed.

text: Today, tourist attractions include:

text:
Battles for Chattanooga Museum – The Museum offers insight of the Battle of Lookout Mountain through soldier figurines and topographical maps.[citation needed]
Lookout Mountain Incline Railway – a National Historic site, with an incline of 72.7%.[17]
Rock City – has multiple different events that occur over the course of the year and rock trails. These rock trails include Lover's Leap, Balanced Rock and Fat Man's Squeeze.
Ruby Falls – view the waterfall from inside the mountain and Lookout Mountain Cave.


document_title: List of countries by apple production

question_text: where do the majority of apples come from

text: List of countries by apple production

text: >1,000,000 tonnes[edit]

text:
Country/Region
Apple production (tonnes)

 China
37,001,601

 United States
4,110,050

 Poland
3,127,694

 Turkey
2,889,894

 India
2,203,400

 Italy
1,991,310

 Brazil
1,810,000

 Chile
1,625,000

 Russia
1,403,000

 France
1,382,900

 Iran
1,335,480

 Argentina
1,250,000

 Ukraine
1,126,800

text: 100,000–1,000,000 tonnes[edit]

text:
Country/Region
Apple production (tonnes)

 Germany
972,404

 Uzbekistan
820,000

 South Africa
795,758

 Japan
793,800

 North Korea
785,000

 Hungary
650,595

 Pakistan
620,000

 Spain
558,900

 Egypt
541,239

 Belarus
511,479

 Morocco
485,642

 Austria
471,420

 Romania
462,935

 New Zealand
448,000

 Algeria
397,529

 South Korea
394,596

 Mexico
375,045

 Syria
334,166

 Australia
289,064

 Moldova
281,849

 Netherlands
281,000

 Canada
269,837

 Greece
251,000

 Azerbaijan
234,771

  Switzerland
227,106

 Belgium
220,400

 Tajikistan
218,300

 United Kingdom
202,900

 Portugal
186,000

 Serbia
178,713

 Lebanon
155,000

 Peru
147,114

 Kyrgyzstan
137,000

 Kazakhstan
132,000

 Israel
131,608

 Macedonia
127,171

 Czech Republic
118,709

 Tunisia
111,000

 Armenia
110,289

text: 50,000–100,000 tonnes[edit]

text:
Country/Region
Apple production (tonnes)

 Turkmenistan
82,000

 Uruguay
80,000

 Lithuania
72,500

 Albania
71,300

 Afghanistan
70,000

 Slovenia
55,300

 Bosnia and Herzegovina
50,023

text: 10,000-50,000 tonnes[edit]

text:
Country/Region
Apple production (tonnes)

   Nepal
48,946

 Iraq
46,500

 Georgia
45,000

 Slovakia
44,481

 Ireland
44,000

 Croatia
42,400

 Jordan
36,377

 El Salvador
34,000

 Bulgaria
30,942

 Bhutan
22,000

 Guatemala
22,000

 Sweden
22,000

 Yemen
22,000

 Libya
20,500

 Denmark
18,731

 Norway
11,440

 Ecuador
10,000

text: <10,000 tonnes[edit]

text:
Country/Region
Apple production (tonnes)

 Latvia
9,449

 Madagascar
7,000

 Zimbabwe
6,500

 Cyprus
6,366

 Montenegro
5,712

 Finland
4,807

 Bolivia
2,000

 Estonia
1,855

 Luxemburg
1,606

 Taiwan
1,590

 Colombia
1,224

 Saint Vincent and the Grenadines
1,196

 Kenya
1,128

 Paraguay
705

 Palestine
650

 Grenada
560

 Honduras
230

 Reunion
80

 Malta
27

 Philippines
25

text: List of Apple producing countries by Area

text:
Rank
Top 10 Countries
Harvested Area (Hac)

1
China
2410170

2
India
312000

2
Poland
193439

3
Russia
186300

4
Turkey
173096

5
United States of America
131210

6
Iran
129754

7
Pakistan
105153

8
Ukraine
103900

9
Uzbekistan
92000