document_title: Chemical reaction

question_text: what type of reaction is acid and base

question_tokens: what type of reaction is acid and base

text: Chemical reaction

text: History

text: Chemical reactions such as combustion in fire, fermentation and the reduction of ores to metals were known since antiquity. Initial theories of transformation of materials were developed by Greek philosophers, such as the Four-Element Theory of Empedocles stating that any substance is composed of the four basic elements – fire, water, air and earth. In the Middle Ages, chemical transformations were studied by Alchemists. They attempted, in particular, to convert lead into gold, for which purpose they used reactions of lead and lead-copper alloys with sulfur.[2]

text: The production of chemical substances that do not normally occur in nature has long been tried, such as the synthesis of sulfuric and nitric acids attributed to the controversial alchemist Jābir ibn Hayyān. The process involved heating of sulfate and nitrate minerals such as copper sulfate, alum and saltpeter. In the 17th century, Johann Rudolph Glauber produced hydrochloric acid and sodium sulfate by reacting sulfuric acid and sodium chloride. With the development of the lead chamber process in 1746 and the Leblanc process, allowing large-scale production of sulfuric acid and sodium carbonate, respectively, chemical reactions became implemented into the industry. Further optimization of sulfuric acid technology resulted in the contact process in the 1880s,[3] and the Haber process was developed in 1909–1910 for ammonia synthesis.[4]

text: From the 16th century, researchers including Jan Baptist van Helmont, Robert Boyle and Isaac Newton tried to establish theories of the experimentally observed chemical transformations. The phlogiston theory was proposed in 1667 by Johann Joachim Becher. It postulated the existence of a fire-like element called "phlogiston", which was contained within combustible bodies and released during combustion. This proved to be false in 1785 by Antoine Lavoisier who found the correct explanation of the combustion as reaction with oxygen from the air.[5]

text: Joseph Louis Gay-Lussac recognized in 1808 that gases always react in a certain relationship with each other. Based on this idea and the atomic theory of John Dalton, Joseph Proust had developed the law of definite proportions, which later resulted in the concepts of stoichiometry and chemical equations.[6]

text: Regarding the organic chemistry, it was long believed that compounds obtained from living organisms were too complex to be obtained synthetically. According to the concept of vitalism, organic matter was endowed with a "vital force" and distinguished from inorganic materials. This separation was ended however by the synthesis of urea from inorganic precursors by Friedrich Wöhler in 1828. Other chemists who brought major contributions to organic chemistry include Alexander William Williamson with his synthesis of ethers and Christopher Kelk Ingold, who, among many discoveries, established the mechanisms of substitution reactions.

text: Equations

text:
Chemical equations are used to graphically illustrate chemical reactions. They consist of chemical or structural formulas of the reactants on the left and those of the products on the right. They are separated by an arrow (→) which indicates the direction and type of the reaction; the arrow is read as the word "yields".[7] The tip of the arrow points in the direction in which the reaction proceeds. A double arrow (⇌) pointing in opposite directions is used for equilibrium reactions. Equations should be balanced according to the stoichiometry, the number of atoms of each species should be the same on both sides of the equation. This is achieved by scaling the number of involved molecules (

A
,
B
,
C

{\displaystyle {\ce {A, B, C}}}

 and

D

{\displaystyle {\ce {D}}}

 in a schematic example below) by the appropriate integers a, b, c and d.[8]

text: More elaborate reactions are represented by reaction schemes, which in addition to starting materials and products show important intermediates or transition states. Also, some relatively minor additions to the reaction can be indicated above the reaction arrow; examples of such additions are water, heat, illumination, a catalyst, etc. Similarly, some minor products can be placed below the arrow, often with a minus sign.

text: Retrosynthetic analysis can be applied to design a complex synthesis reaction. Here the analysis starts from the products, for example by splitting selected chemical bonds, to arrive at plausible initial reagents. A special arrow (⇒) is used in retro reactions.[9]

text: Elementary reactions

text: The elementary reaction is the smallest division into which a chemical reaction can be decomposed, it has no intermediate products.[10] Most experimentally observed reactions are built up from many elementary reactions that occur in parallel or sequentially. The actual sequence of the individual elementary reactions is known as reaction mechanism. An elementary reaction involves a few molecules, usually one or two, because of the low probability for several molecules to meet at a certain time.[11]

text: The most important elementary reactions are unimolecular and bimolecular reactions. Only one molecule is involved in a unimolecular reaction; it is transformed by an isomerization or a dissociation into one or more other molecules. Such reactions require the addition of energy in the form of heat or light. A typical example of a unimolecular reaction is the cis–trans isomerization, in which the cis-form of a compound converts to the trans-form or vice versa.[12]

text: In a typical dissociation reaction, a bond in a molecule splits (ruptures) resulting in two molecular fragments. The splitting can be homolytic or heterolytic. In the first case, the bond is divided so that each product retains an electron and becomes a neutral radical. In the second case, both electrons of the chemical bond remain with one of the products, resulting in charged ions. Dissociation plays an important role in triggering chain reactions, such as hydrogen–oxygen or polymerization reactions.

text: For bimolecular reactions, two molecules collide and react with each other. Their merger is called chemical synthesis or an addition reaction.

text: Another possibility is that only a portion of one molecule is transferred to the other molecule. This type of reaction occurs, for example, in redox and acid-base reactions. In redox reactions, the transferred particle is an electron, whereas in acid-base reactions it is a proton. This type of reaction is also called metathesis.

text: for example

text: Chemical equilibrium

text: Most chemical reactions are reversible, that is they can and do run in both directions. The forward and reverse reactions are competing with each other and differ in reaction rates. These rates depend on the concentration and therefore change with time of the reaction: the reverse rate gradually increases and becomes equal to the rate of the forward reaction, establishing the so-called chemical equilibrium. The time to reach equilibrium depends on such parameters as temperature, pressure and the materials involved, and is determined by the minimum free energy. In equilibrium, the Gibbs free energy must be zero. The pressure dependence can be explained with the Le Chatelier's principle. For example, an increase in pressure due to decreasing volume causes the reaction to shift to the side with the fewer moles of gas.[13]

text: The reaction yield stabilizes at equilibrium, but can be increased by removing the product from the reaction mixture or changed by increasing the temperature or pressure. A change in the concentrations of the reactants does not affect the equilibrium constant, but does affect the equilibrium position.

text: Thermodynamics

text: Chemical reactions are determined by the laws of thermodynamics. Reactions can proceed by themselves if they are exergonic, that is if they release energy. The associated free energy of the reaction is composed of two different thermodynamic quantities, enthalpy and entropy:[14]

text: Reactions can be exothermic, where ΔH is negative and energy is released. Typical examples of exothermic reactions are precipitation and crystallization, in which ordered solids are formed from disordered gaseous or liquid phases. In contrast, in endothermic reactions, heat is consumed from the environment. This can occur by increasing the entropy of the system, often through the formation of gaseous reaction products, which have high entropy. Since the entropy increases with temperature, many endothermic reactions preferably take place at high temperatures. On the contrary, many exothermic reactions such as crystallization occur at low temperatures. Changes in temperature can sometimes reverse the sign of the enthalpy of a reaction, as for the carbon monoxide reduction of molybdenum dioxide:

text: This reaction to form carbon dioxide and molybdenum is endothermic at low temperatures, becoming less so with increasing temperature.[15] ΔH° is zero at 7003185500000000000♠1855 K, and the reaction becomes exothermic above that temperature.

text: Changes in temperature can also reverse the direction tendency of a reaction. For example, the water gas shift reaction

text: is favored by low temperatures, but its reverse is favored by high temperature. The shift in reaction direction tendency occurs at 7003110000000000000♠1100 K.[15]

text: Reactions can also be characterized by the internal energy which takes into account changes in the entropy, volume and chemical potential. The latter depends, among other things, on the activities of the involved substances.[16]

text: Kinetics

text: The speed at which reactions takes place is studied by reaction kinetics. The rate depends on various parameters, such as:

text:
Reactant concentrations, which usually make the reaction happen at a faster rate if raised through increased collisions per unit time. Some reactions, however, have rates that are independent of reactant concentrations. These are called zero order reactions.
Surface area available for contact between the reactants, in particular solid ones in heterogeneous systems. Larger surface areas lead to higher reaction rates.
Pressure – increasing the pressure decreases the volume between molecules and therefore increases the frequency of collisions between the molecules.
Activation energy, which is defined as the amount of energy required to make the reaction start and carry on spontaneously. Higher activation energy implies that the reactants need more energy to start than a reaction with a lower activation energy.
Temperature, which hastens reactions if raised, since higher temperature increases the energy of the molecules, creating more collisions per unit time,
The presence or absence of a catalyst. Catalysts are substances which change the pathway (mechanism) of a reaction which in turn increases the speed of a reaction by lowering the activation energy needed for the reaction to take place. A catalyst is not destroyed or changed during a reaction, so it can be used again.
For some reactions, the presence of electromagnetic radiation, most notably ultraviolet light, is needed to promote the breaking of bonds to start the reaction. This is particularly true for reactions involving radicals.

text: Several theories allow calculating the reaction rates at the molecular level. This field is referred to as reaction dynamics. The rate v of a first-order reaction, which could be disintegration of a substance A, is given by:

text: Its integration yields:

text: Here k is first-order rate constant having dimension 1/time, [A](t) is concentration at a time t and [A]0 is the initial concentration. The rate of a first-order reaction depends only on the concentration and the properties of the involved substance, and the reaction itself can be described with the characteristic half-life. More than one time constant is needed when describing reactions of higher order. The temperature dependence of the rate constant usually follows the Arrhenius equation:

text: where Ea is the activation energy and kB is the Boltzmann constant. One of the simplest models of reaction rate is the collision theory. More realistic models are tailored to a specific problem and include the transition state theory, the calculation of the potential energy surface, the Marcus theory and the Rice–Ramsperger–Kassel–Marcus (RRKM) theory.[17]

text: Reaction types

text: Four basic types

text: Synthesis

text: In a synthesis reaction, two or more simple substances combine to form a more complex substance. These reactions are in the general form:

text: Two or more reactants yielding one product is another way to identify a synthesis reaction. One example of a synthesis reaction is the combination of iron and sulfur to form iron(II) sulfide:

text: Another example is simple hydrogen gas combined with simple oxygen gas to produce a more complex substance, such as water.[18]

text: Decomposition

text: A decomposition reaction is when a more complex substance breaks down into its more simple parts. It is thus the opposite of a synthesis reaction, and can be written as[18][19]

text: One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen gas:

text: Single replacement

text: In a single replacement reaction, a single uncombined element replaces another in a compound; in other words, one element trades places with another element in a compound[18] These reactions come in the general form of:

text: One example of a single displacement reaction is when magnesium replaces hydrogen in water to make magnesium hydroxide and hydrogen gas:

text: Double replacement

text: In a double replacement reaction, the anions and cations of two compounds switch places and form two entirely different compounds.[18] These reactions are in the general form:[19]

text: For example, when barium chloride (BaCl2) and magnesium sulfate (MgSO4) react, the SO42− anion switches places with the 2Cl− anion, giving the compounds BaSO4 and MgCl2.

text: Another example of a double displacement reaction is the reaction of lead(II) nitrate with potassium iodide to form lead(II) iodide and potassium nitrate:

text: Oxidation and reduction

text: Redox reactions can be understood in terms of transfer of electrons from one involved species (reducing agent) to another (oxidizing agent). In this process, the former species is oxidized and the latter is reduced. Though sufficient for many purposes, these descriptions are not precisely correct. Oxidation is better defined as an increase in oxidation state, and reduction as a decrease in oxidation state. In practice, the transfer of electrons will always change the oxidation state, but there are many reactions that are classed as "redox" even though no electron transfer occurs (such as those involving covalent bonds).[20][21]

text: In the following redox reaction, hazardous sodium metal reacts with toxic chlorine gas to form the ionic compound sodium chloride, or common table salt:

text: In the reaction, sodium metal goes from an oxidation state of 0 (as it is a pure element) to +1: in other words, the sodium lost one electron and is said to have been oxidized. On the other hand, the chlorine gas goes from an oxidation of 0 (it is also a pure element) to −1: the chlorine gains one electron and is said to have been reduced. Because the chlorine is the one reduced, it is considered the electron acceptor, or in other words, induces oxidation in the sodium – thus the chlorine gas is considered the oxidizing agent. Conversely, the sodium is oxidized or is the electron donor, and thus induces reduction in the other species and is considered the reducing agent.

text:
Which of the involved reactants would be reducing or oxidizing agent can be predicted from the electronegativity of their elements. Elements with low electronegativity, such as most metals, easily donate electrons and oxidize – they are reducing agents. On the contrary, many ions with high oxidation numbers, such as H
2O
2, MnO−
4, CrO
3, Cr
2O2−
7, OsO
4 can gain one or two extra electrons and are strong oxidizing agents.

text: The number of electrons donated or accepted in a redox reaction can be predicted from the electron configuration of the reactant element. Elements try to reach the low-energy noble gas configuration, and therefore alkali metals and halogens will donate and accept one electron respectively. Noble gases themselves are chemically inactive.[22]

text: An important class of redox reactions are the electrochemical reactions, where electrons from the power supply are used as the reducing agent. These reactions are particularly important for the production of chemical elements, such as chlorine[23] or aluminium. The reverse process in which electrons are released in redox reactions and can be used as electrical energy is possible and used in batteries.

text: Complexation

text: In complexation reactions, several ligands react with a metal atom to form a coordination complex. This is achieved by providing lone pairs of the ligand into empty orbitals of the metal atom and forming dipolar bonds. The ligands are Lewis bases, they can be both ions and neutral molecules, such as carbon monoxide, ammonia or water. The number of ligands that react with a central metal atom can be found using the 18-electron rule, saying that the valence shells of a transition metal will collectively accommodate 18 electrons, whereas the symmetry of the resulting complex can be predicted with the crystal field theory and ligand field theory. Complexation reactions also include ligand exchange, in which one or more ligands are replaced by another, and redox processes which change the oxidation state of the central metal atom.[24]

text: Acid-base reactions

text: In the Brønsted–Lowry acid–base theory, an acid-base reaction involves a transfer of protons (H+) from one species (the acid) to another (the base). When a proton is removed from an acid, the resulting species is termed that acid's conjugate base. When the proton is accepted by a base, the resulting species is termed that base's conjugate acid.[25] In other words, acids act as proton donors and bases act as proton acceptors according to the following equation:

text: The reverse reaction is possible, and thus the acid/base and conjugated base/acid are always in equilibrium. The equilibrium is determined by the acid and base dissociation constants (Ka and Kb) of the involved substances. A special case of the acid-base reaction is the neutralization where an acid and a base, taken at exactly same amounts, form a neutral salt.

text: Acid-base reactions can have different definitions depending on the acid-base concept employed. Some of the most common are:

text:
Arrhenius definition: Acids dissociate in water releasing H3O+ ions; bases dissociate in water releasing OH− ions.
Brønsted-Lowry definition: Acids are proton (H+) donors, bases are proton acceptors; this includes the Arrhenius definition.
Lewis definition: Acids are electron-pair acceptors, bases are electron-pair donors; this includes the Brønsted-Lowry definition.

text: Precipitation

text: Precipitation is the formation of a solid in a solution or inside another solid during a chemical reaction. It usually takes place when the concentration of dissolved ions exceeds the solubility limit[26] and forms an insoluble salt. This process can be assisted by adding a precipitating agent or by removal of the solvent. Rapid precipitation results in an amorphous or microcrystalline residue and slow process can yield single crystals. The latter can also be obtained by recrystallization from microcrystalline salts.[27]

text: Solid-state reactions

text: Reactions can take place between two solids. However, because of the relatively small diffusion rates in solids, the corresponding chemical reactions are very slow in comparison to liquid and gas phase reactions. They are accelerated by increasing the reaction temperature and finely dividing the reactant to increase the contacting surface area.[28]

text: Reactions at the solid|gas interface

text: Reaction can take place at the solid|gas interface, surfaces at very low pressure such as ultra-high vacuum. Via scanning tunneling microscopy, it is possible to observe reactions at the solid|gas interface in real space, if the time scale of the reaction is in the correct range.[29][30] Reactions at the solid|gas interface are in some cases related to catalysis.

text: Photochemical reactions

text: In photochemical reactions, atoms and molecules absorb energy (photons) of the illumination light and convert into an excited state. They can then release this energy by breaking chemical bonds, thereby producing radicals. Photochemical reactions include hydrogen–oxygen reactions, radical polymerization, chain reactions and rearrangement reactions.[31]

text: Many important processes involve photochemistry. The premier example is photosynthesis, in which most plants use solar energy to convert carbon dioxide and water into glucose, disposing of oxygen as a side-product. Humans rely on photochemistry for the formation of vitamin D, and vision is initiated by a photochemical reaction of rhodopsin.[12] In fireflies, an enzyme in the abdomen catalyzes a reaction that results in bioluminescence.[32] Many significant photochemical reactions, such as ozone formation, occur in the Earth atmosphere and constitute atmospheric chemistry.

text: Catalysis

text: In catalysis, the reaction does not proceed directly, but through reaction with a third substance known as catalyst. Although the catalyst takes part in the reaction, it is returned to its original state by the end of the reaction and so is not consumed. However, it can be inhibited, deactivated or destroyed by secondary processes. Catalysts can be used in a different phase (heterogeneous) or in the same phase (homogeneous) as the reactants. In heterogeneous catalysis, typical secondary processes include coking where the catalyst becomes covered by polymeric side products. Additionally, heterogeneous catalysts can dissolve into the solution in a solid–liquid system or evaporate in a solid–gas system. Catalysts can only speed up the reaction – chemicals that slow down the reaction are called inhibitors.[33][34] Substances that increase the activity of catalysts are called promoters, and substances that deactivate catalysts are called catalytic poisons. With a catalyst, a reaction which is kinetically inhibited by a high activation energy can take place in circumvention of this activation energy.

text: Heterogeneous catalysts are usually solids, powdered in order to maximize their surface area. Of particular importance in heterogeneous catalysis are the platinum group metals and other transition metals, which are used in hydrogenations, catalytic reforming and in the synthesis of commodity chemicals such as nitric acid and ammonia. Acids are an example of a homogeneous catalyst, they increase the nucleophilicity of carbonyls, allowing a reaction that would not otherwise proceed with electrophiles. The advantage of homogeneous catalysts is the ease of mixing them with the reactants, but they may also be difficult to separate from the products. Therefore, heterogeneous catalysts are preferred in many industrial processes.[35]

text: Reactions in organic chemistry

text: In organic chemistry, in addition to oxidation, reduction or acid-base reactions, a number of other reactions can take place which involve covalent bonds between carbon atoms or carbon and heteroatoms (such as oxygen, nitrogen, halogens, etc.). Many specific reactions in organic chemistry are name reactions designated after their discoverers.

text: Substitution

text: In a substitution reaction, a functional group in a particular chemical compound is replaced by another group.[36] These reactions can be distinguished by the type of substituting species into a nucleophilic, electrophilic or radical substitution.

text: In the first type, a nucleophile, an atom or molecule with an excess of electrons and thus a negative charge or partial charge, replaces another atom or part of the "substrate" molecule. The electron pair from the nucleophile attacks the substrate forming a new bond, while the leaving group departs with an electron pair. The nucleophile may be electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged. Examples of nucleophiles are hydroxide ion, alkoxides, amines and halides. This type of reaction is found mainly in aliphatic hydrocarbons, and rarely in aromatic hydrocarbon. The latter have high electron density and enter nucleophilic aromatic substitution only with very strong electron withdrawing groups. Nucleophilic substitution can take place by two different mechanisms, SN1 and SN2. In their names, S stands for substitution, N for nucleophilic, and the number represents the kinetic order of the reaction, unimolecular or bimolecular.[37]

text: The SN1 reaction proceeds in two steps. First, the leaving group is eliminated creating a carbocation. This is followed by a rapid reaction with the nucleophile.[38]

text: In the SN2 mechanism, the nucleophile forms a transition state with the attacked molecule, and only then the leaving group is cleaved. These two mechanisms differ in the stereochemistry of the products. SN1 leads to the non-stereospecific addition and does not result in a chiral center, but rather in a set of geometric isomers (cis/trans). In contrast, a reversal (Walden inversion) of the previously existing stereochemistry is observed in the SN2 mechanism.[39]

text: Electrophilic substitution is the counterpart of the nucleophilic substitution in that the attacking atom or molecule, an electrophile, has low electron density and thus a positive charge. Typical electrophiles are the carbon atom of carbonyl groups, carbocations or sulfur or nitronium cations. This reaction takes place almost exclusively in aromatic hydrocarbons, where it is called electrophilic aromatic substitution. The electrophile attack results in the so-called σ-complex, a transition state in which the aromatic system is abolished. Then, the leaving group, usually a proton, is split off and the aromaticity is restored. An alternative to aromatic substitution is electrophilic aliphatic substitution. It is similar to the nucleophilic aliphatic substitution and also has two major types, SE1 and SE2[40]

text: In the third type of substitution reaction, radical substitution, the attacking particle is a radical.[36] This process usually takes the form of a chain reaction, for example in the reaction of alkanes with halogens. In the first step, light or heat disintegrates the halogen-containing molecules producing the radicals. Then the reaction proceeds as an avalanche until two radicals meet and recombine.[41]

text: Addition and elimination

text: The addition and its counterpart, the elimination, are reactions which change the number of substitutents on the carbon atom, and form or cleave multiple bonds. Double and triple bonds can be produced by eliminating a suitable leaving group. Similar to the nucleophilic substitution, there are several possible reaction mechanisms which are named after the respective reaction order. In the E1 mechanism, the leaving group is ejected first, forming a carbocation. The next step, formation of the double bond, takes place with elimination of a proton (deprotonation). The leaving order is reversed in the E1cb mechanism, that is the proton is split off first. This mechanism requires participation of a base.[42] Because of the similar conditions, both reactions in the E1 or E1cb elimination always compete with the SN1 substitution.[43]

text: The E2 mechanism also requires a base, but there the attack of the base and the elimination of the leaving group proceed simultaneously and produce no ionic intermediate. In contrast to the E1 eliminations, different stereochemical configurations are possible for the reaction product in the E2 mechanism, because the attack of the base preferentially occurs in the anti-position with respect to the leaving group. Because of the similar conditions and reagents, the E2 elimination is always in competition with the SN2-substitution.[44]

text: The counterpart of elimination is the addition where double or triple bonds are converted into single bonds. Similar to the substitution reactions, there are several types of additions distinguished by the type of the attacking particle. For example, in the electrophilic addition of hydrogen bromide, an electrophile (proton) attacks the double bond forming a carbocation, which then reacts with the nucleophile (bromine). The carbocation can be formed on either side of the double bond depending on the groups attached to its ends, and the preferred configuration can be predicted with the Markovnikov's rule.[45] This rule states that "In the heterolytic addition of a polar molecule to an alkene or alkyne, the more electronegative (nucleophilic) atom (or part) of the polar molecule becomes attached to the carbon atom bearing the smaller number of hydrogen atoms."[46]

text: If the addition of a functional group takes place at the less substituted carbon atom of the double bond, then the electrophilic substitution with acids is not possible. In this case, one has to use the hydroboration–oxidation reaction, where in the first step, the boron atom acts as electrophile and adds to the less substituted carbon atom. At the second step, the nucleophilic hydroperoxide or halogen anion attacks the boron atom.[47]

text: While the addition to the electron-rich alkenes and alkynes is mainly electrophilic, the nucleophilic addition plays an important role for the carbon-heteroatom multiple bonds, and especially its most important representative, the carbonyl group. This process is often associated with an elimination, so that after the reaction the carbonyl group is present again. It is therefore called addition-elimination reaction and may occur in carboxylic acid derivatives such as chlorides, esters or anhydrides. This reaction is often catalyzed by acids or bases, where the acids increase by the electrophilicity of the carbonyl group by binding to the oxygen atom, whereas the bases enhance the nucleophilicity of the attacking nucleophile.[48]

text: Nucleophilic addition of a carbanion or another nucleophile to the double bond of an alpha, beta unsaturated carbonyl compound can proceed via the Michael reaction, which belongs to the larger class of conjugate additions. This is one of the most useful methods for the mild formation of C–C bonds.[49][50][51]

text: Some additions which can not be executed with nucleophiles and electrophiles, can be succeeded with free radicals. As with the free-radical substitution, the radical addition proceeds as a chain reaction, and such reactions are the basis of the free-radical polymerization.[52]

text: Other organic reaction mechanisms

text: In a rearrangement reaction, the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. These include hydride shift reactions such as the Wagner-Meerwein rearrangement, where a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. Most rearrangements are associated with the breaking and formation of new carbon-carbon bonds. Other examples are sigmatropic reaction such as the Cope rearrangement.[53]

text: Cyclic rearrangements include cycloadditions and, more generally, pericyclic reactions, wherein two or more double bond-containing molecules form a cyclic molecule. An important example of cycloaddition reaction is the Diels–Alder reaction (the so-called [4+2] cycloaddition) between a conjugated diene and a substituted alkene to form a substituted cyclohexene system.[54]

text: Whether a certain cycloaddition would proceed depends on the electronic orbitals of the participating species, as only orbitals with the same sign of wave function will overlap and interact constructively to form new bonds. Cycloaddition is usually assisted by light or heat. These perturbations result in different arrangement of electrons in the excited state of the involved molecules and therefore in different effects. For example, the [4+2] Diels-Alder reactions can be assisted by heat whereas the [2+2] cycloaddition is selectively induced by light.[55] Because of the orbital character, the potential for developing stereoisomeric products upon cycloaddition is limited, as described by the Woodward–Hoffmann rules.[56]

text: Biochemical reactions

text: Biochemical reactions are mainly controlled by enzymes. These proteins can specifically catalyze a single reaction, so that reactions can be controlled very precisely. The reaction takes place in the active site, a small part of the enzyme which is usually found in a cleft or pocket lined by amino acid residues, and the rest of the enzyme is used mainly for stabilization. The catalytic action of enzymes relies on several mechanisms including the molecular shape ("induced fit"), bond strain, proximity and orientation of molecules relative to the enzyme, proton donation or withdrawal (acid/base catalysis), electrostatic interactions and many others.[57]

text: The biochemical reactions that occur in living organisms are collectively known as metabolism. Among the most important of its mechanisms is the anabolism, in which different DNA and enzyme-controlled processes result in the production of large molecules such as proteins and carbohydrates from smaller units.[58] Bioenergetics studies the sources of energy for such reactions. An important energy source is glucose, which can be produced by plants via photosynthesis or assimilated from food. All organisms use this energy to produce adenosine triphosphate (ATP), which can then be used to energize other reactions.

text: Applications

text: Chemical reactions are central to chemical engineering where they are used for the synthesis of new compounds from natural raw materials such as petroleum and mineral ores. It is essential to make the reaction as efficient as possible, maximizing the yield and minimizing the amount of reagents, energy inputs and waste. Catalysts are especially helpful for reducing the energy required for the reaction and increasing its reaction rate.[59][60]

text: Some specific reactions have their niche applications. For example, the thermite reaction is used to generate light and heat in pyrotechnics and welding. Although it is less controllable than the more conventional oxy-fuel welding, arc welding and flash welding, it requires much less equipment and is still used to mend rails, especially in remote areas.[61]

text: Monitoring

text: Mechanisms of monitoring chemical reactions depend strongly on the reaction rate. Relatively slow processes can be analyzed in situ for the concentrations and identities of the individual ingredients. Important tools of real time analysis are the measurement of pH and analysis of optical absorption (color) and emission spectra. A less accessible but rather efficient method is introduction of a radioactive isotope into the reaction and monitoring how it changes over time and where it moves to; this method is often used to analyze redistribution of substances in the human body. Faster reactions are usually studied with ultrafast laser spectroscopy where utilization of femtosecond lasers allows short-lived transition states to be monitored at time scaled down to a few femtoseconds.[62]


document_title: Hannah Montana (season 2)

question_text: which episode of hannah montana is selena gomez in

root

text: Hannah Montana (season 2)

text: Premieres[edit]

text: The second season premiered with five new episodes in one week from April 23–27, 2007. "(We're So Sorry) Uncle Earl" aired in a week-long Disney Channel event called "Sweet Niblets, We're Related?". Disney Channel UK premiered five new Hannah Montana episodes for "Montana May", "(We're So Sorry) Uncle Earl", "You Didn't Say It Was Your Birthday", "Joannie B. Goode", "The Test of My Love", and "Yet Another Side of Me". The second series premiered in June 2007 on Disney Channel UK; it then aired on free-to-view Channel Five just like season one in October 2009, however Five only has rights to air half the season. It airs before Wizards of Waverly Place.

tag: p

text: Opening sequence[edit]

text: For season two, the only major changes were the addition of Moises Arias as a cast member and the clips of season 2 included with season 1 clips of the cast member shown and causes the scene of the switch from Miley to Hannah Montana in the middle of the theme song has deleted. Stage and features episode clips of each cast member when each cast member's name appears. Each cast member's name is "wiped" on the screen in a marquee-light-style. Moises Arias becomes a regular cast member for season 2. The sequence then switches to full-screen episode clips. Season 2 clips were used for the second season (Some season one clips are put in). The creator's names appear in the last clip. The show's title logo design appears at the beginning, and again at the end, of the sequence

text: Casting[edit]

text: Moisés Arias becomes a regular cast member. In "My Best-Friend's Boyfriend", Larry David was approached by the producers about being on the show when he attended a Hannah Montana taping with his two daughters, who were fans of the show. He agreed, and appeared in the episode with his daughters, playing himself as a "frustrated restaurant patron". David's daughters are "huge fans" of Hannah Montana. Heather Locklear was also convinced to guest star after attending with her kids. Camryn Manheim and Brooke Shields also have made guest appearances because their kids enjoy the show. John D'Aquino and Madison Pettis from Cory in the House make guest appearances as their characters in a special crossover episode. The Jonas Brothers also guest star in an episode.

text: Dwayne "The Rock" Johnson appears in "Don't Stop 'Til You Get the Phone" as part of the Rock Block, in which he guest-starred in episodes of Hannah Montana and Cory in the House as a promotion for Disney's film The Game Plan.

text: Music[edit]

text: "I Want You to Want Me... to Go to Florida" features the ballad "Ready, Set, Don't Go" by Billy Ray Cyrus. It details his feelings concerning his daughter Miley's move to Los Angeles to star in Hannah Montana, while he stayed behind in Nashville. The episode also features the song "If Cupid Had a Heart", by Julie Griffin, and written by Gordon Pogoda. Mikayla (Selena Gomez), lip-syncs it in the episode. A soundtrack for the season featuring 10 songs sung by Miley Cyrus as Hannah Montana was released on June 26, 2007.

text: DVD releases[edit]

text: The second, Wish Gone Amiss Weekend DVD, which was released November 27, 2007, features the "When You Wish You Were the Star" episode and a Hannah Montana bonus "I Wish I May, I Wish I Might: A Guide to Making Wishes" hosted by Jason Earles. The Volume 4: One in a Million DVD which released January 29, 2008, includes four episodes of Hannah Montana. "Lilly's Mom Has Got It Goin' On", "Me and Mr. Jonas and Mr. Jonas and Mr. Jonas", "I Will Always Loathe You" and "That's What Friends Are For?" were included in the DVD. The DVD also features a That's So Raven episode "Run Raven Run", "Come Feud with Me" - the top 10 Disney Channel feuds, as well as the "One in a Million" and "True Friend" music videos. In Australia, following the release of the Complete First Season on DVD in November, Season 2: Part 1 and Season 2: Part 2 were released soon after. In part one, episodes 1-15 were included, while remaining episodes 16-29 were released in part 2. On the case, there are images from the episode "No Sugar, Sugar", but the episode was not released on the disc. A full season collection was released on November 25, 2009.

text: Episodes[edit]

text: Season 2 started with a week of 5 new episodes. The average ratings for the 5 new episodes were 3.7 million viewers. Season 2 had several special episodes and marathons. The first special was "Achy Jakey Heart", in which Miley revealed her secret to Jake Ryan (Cody Linley). The second special, "Me and Mr. Jonas and Mr. Jonas and Mr. Jonas", which guest starred the Jonas Brothers, was aired with the premiere of High School Musical 2. Dwayne "The Rock" Johnson appeared in "Don't Stop 'Til You Get the Phone" as part of the Rock Block, which seen him guest-star in episodes of Hannah Montana and Cory in the House as a promotion for Disney's film The Game Plan. "(We're So Sorry) Uncle Earl" aired in a week-long Disney Channel event "Sweet Niblets, We're Related?". In 3 episodes this season, Hannah Montana wins an award.

text:
Hannah Montana Season 2 episodes

No. in
series
No. in
season
Title
Directed by
Written by
Original air date
Prod.
code
Viewers
(millions)

27
1
"Me and Rico Down by the Schoolyard"
Roger S. Christiansen
Heather Wordham
April 23, 2007 (2007-04-23)
203
3.5[1]

Miley, Lilly, and Oliver start high school and Rico (who is also in high school after skipping a few grades) soon learns what he thinks is Miley's "big secret" and blackmails her with it by making her be his girlfriend. Lilly and Oliver later learn that the "secret" was just Miley's attachment to her teddy bear. At the end, Rico makes Miley feel bad so she tells him to kiss her on the cheek, but he turns his head and he kisses her on the lips. Meanwhile, Jackson's new friend Thor causes him major humiliation.
First appearance as a main cast member: Moises Arias as Rico Suave
Guest stars: Andrew Caldwell as Thor
Hannah song featured: "Make Some Noise"

28
2
"Cuffs Will Keep Us Together"
Roger S. Christiansen
Steven Peterman
April 24, 2007 (2007-04-24)
201
3.5[1]

Miley and Lilly start a fight after Lilly doesn't choose Miley first in a Flag-Football game in gym class. After Oliver gets annoyed with their behavior, he handcuffs them together right before Hannah's big award show. The girls have to work it out so Hannah can get ready. Robby gives Jackson the silent treatment when he gets tired of telling Jackson the same thing multiple times.
Guest stars: Romi Dames as Traci VanHorn, Morgan York as Sarah, Hayley Chase as Joannie Palumbo
Hannah song featured: "True Friend"

29
3
"You Are So Sue-able to Me"
Roger S. Christiansen
Sally Lapiduss
April 25, 2007 (2007-04-25)
202
3.9[1]

Lilly gets asked out to a dance, but Miley thinks she acts too much like "one of the guys" and gives her a big makeover, however the person who asks her out doesn't like "the new Lilly" so he stands Lilly up, prompting Miley and Lilly to take him to "The Teen Court" (A TV show involving teens on 'trial' for causing pain and humiliation to others). Jackson wins two tickets to the Lakers game and invites Thor, but Robby assumes that it will be a "father and son" outing, leaving Jackson trying to decide between the two without hurting the other's feelings. At the end of the episode Miley realizes it was wrong to change Lilly.
Absent: Mitchel Musso as Oliver Oken, Moises Arias as Rico
Guest stars: Andrew Caldwell as Thor, Shanica Knowles as Amber Addison, Anna Maria Perez de Taglé as Ashley Dewitt, Morgan York as Sarah
Hannah song featured: "One in a Million"

30
4
"Get Down, Study-udy-udy"
Roger S. Christiansen
Andrew Green
April 26, 2007 (2007-04-26)
204
3.7[1]

When Miley receives a poor mid-term grade in Biology, Robby says she must ace her mid-term exam or it's no European tour for Hannah. Meanwhile, Jackson volunteers to take care of Thor's pet parrot, Snowball, but the talking bird creates problems for Jackson.
Guest stars: Andrew Caldwell as Thor, Erin Matthews as Ms. Kunkle and Tiffany Thornton as Becky
Hannah song featured: "Nobody's Perfect"

31
5
"I Am Hannah, Hear Me Croak"
Roger S. Christiansen
Michael Poryes
April 27, 2007 (2007-04-27)
206
3.5[1]

Miley loses her voice after six encores at a Hannah concert, and learns that only surgery will fix the problem. Fearful of what a botched surgery could do to her career, Miley's late mom (Brooke Shields) appears in Miley's dreams to reassure her that nothing would change if Miley's surgery didn't go right. In the end, Robby has a separate dream involving Miley and her mother.
Co-stars: Patrick Ryan Anderson as Todd, Ryan Newman as Young Miley, Chris Brochu as Dex, Ryan Adkisson as Young Jackson
Guest stars: Greg Baker as Mr Corelli, Tim Russ as Dr Meyer
Special guest star: Brooke Shields as Miley's mom
Hannah songs featured: "I Got Nerve", "Life's What You Make It", "You and Me Together"
Note: When Miley is talking to her dad, Jackson is there, but in the next scene, he is gone, but is there again in the scene after that. Jackson may have moved out of the scene to get something.

32
6
"You Gotta Not Fight for Your Right to Party"
Jody Margolin Hahn
Steven James Meyer
May 4, 2007 (2007-05-04)
207
3.5[2]

After Jackson's bathroom is destroyed, Robby makes Miley share hers with him, resulting in a war between Miley and Jackson. Robby grounds Miley and Jackson because of the fighting but they sneak out using Thor's truck. When the truck nearly falls off a cliff (that turns out to be no higher than 2 feet) they managed to escape, they are brought closer together. Meanwhile, Lilly and Oliver disguise themselves as Miley and Jackson to hide their absence from Robby.

33
7
"My Best Friend's Boyfriend"
Roger S. Christiansen
Jay J. Demopoulos
May 18, 2007 (2007-05-18)
209
3.8[3]

Lilly dates a boy, Lucas, and she realizes he is the greatest boyfriend she ever has, and Miley couldn't be happier for her, until she realizes that she's isn't happy with the two, and decided that she won't speak to her, till she caught Lucas kissing another girl and tells Lilly about it, but she thinks that Miley is jealous and snubbed her. Lilly then finds that Miley is right about Lucas and dumps him. Meanwhile, Rico sets an alarm system because someone or something stole his sunglasses. But Jackson gets annoyed by the alarm system.
Guest stars: Sterling Knight, Mitzi McCall, Larry David
Co-stars: Austin Butler, Kelly Gould, Cazzie David, Romy David

34
8
"Take This Job and Love It"
Roger S. Christiansen
Sally Lapiduss
June 16, 2007 (2007-06-16)
210
4.5[4]

Hannah volunteers Roxy to work for President Martinez after she ruins Hannah's date with her backup dancer. Meanwhile, Jackson pretends to be a professional motor-cross racer to impress a girl.
Guest stars: Frances Callier, John D'Aquino, Madison Pettis, Bobby Costanzo
Hannah song featured: "Nobody's Perfect"

35
9
"Achy Jakey Heart" (Part 1)
Rich Correll
Douglas Lieblein
June 24, 2007 (2007-06-24)
211
7.4[5]

When Jake returns and re-kindles his relationship with Miley, she begins to feel guilty for keeping her "Hannah" secret from him; when Jackson gets fired, he and Oliver open a stand that sells "Cheese Jerky", which becomes more successful than Rico's. Rico then attempts to steal their recipe.
Guest stars: Cody Linley as Jake Ryan, R. Brandon Johnson as Brian Winters, Nicole Gale Anderson as Marissa Hughes
Anita Morales, Brian Britt, Johnny Ferrara, Sanjiv Parikh
Hannah song featured: "One in a Million"

36
10
"Achy Jakey Heart" (Part 2)
Roger S. Christiansen
Andrew Green
June 24, 2007 (2007-06-24)
212
7.4[5]

When Jake creates a "normal person" disguise for his dates with Miley but still expects the star treatment he's been used to for so long, Miley considers breaking up with him, but fears he will get mad and reveal her secret. Meanwhile Jackson and Oliver's Cheese Jerky stand goes from success to failure when they can't earn a profit.
Guest stars: Shanica Knowles as Amber Addison, Anna Maria Perez de Taglé as Ashley Dewitt, Noah Cyrus as Little Girl
Hannah song featured: "One in a Million"

37
11
"Sleepwalk This Way"
Roger S. Christansen
Heather Wordham
July 7, 2007 (2007-07-07)
213
5.3[4]

Robby wrote a new song but he refuse to play on the guitar. Miley found the song and read the lyrics, only to find that the lyrics don't make any sense and starting hating it, without telling her dad. Because she hates the song, she start suffering from sleepwalking. It happens again in school during class when Miley had insulted a science teacher's appearance (while sleepwalking) and got in trouble and got sent to the principal's office as a result. She return home and tells Jackson about how she hated the song and needs to confess to her dad. Unfortunately, Robby overhears it and got upset. She tells him about, only to discover that she wrote the song when she was 5. The real song is Bigger than Us made a big hit.
Guest stars: Erin Matthews, Teo Olivares
Hannah song featured: "Bigger Than Us"

38
12
"When You Wish You Were the Star"
Roger S. Christansen
Douglas Lieblein
July 14, 2007 (2007-07-14)
205
5.1[6]

When Hannah and Lola have to turn down a date with Jesse McCartney because Miley and Lilly have a science project due the next day, Miley wishes on a shooting star that she didn't have dual lives. When her wish comes true, Hannah finds that being a superstar 24/7 isn't all it's cracked up to be when she realizes Miley never met Lilly and Oliver. So Lilly is friends with Amber and Ashley, Oliver sells peeks into Hannah’s windows with Rico, Jackson moved out and became a hermit and her dad Robbie married a young gold digger named Candace. This episode is based on the 1946 movie, It's a Wonderful Life.
Special guest star: Jesse McCartney as himself
Guest stars: Frances Callier as Roxy Roker/Angel, Shanica Knowles as Amber Addison, Anna Maria Perez de Taglé as Ashley Dewitt, Romi Dames as Traci VanHorn
Hannah song featured: "Old Blue Jeans", "The Best of Both Worlds"
Note: This was part of a Disney Channel event, "Wish Gone Amiss Weekend", which also included Cory in the House and The Suite Life of Zack and Cody

39
13
"I Want You to Want Me... to Go to Florida"
Roger S. Christansen
Michael Poryes
July 21, 2007 (2007-07-21)
208
4.5[7]

Hannah wants to go to Florida for a charity concert to beat her singing rival Mikayla, but when Robby injures his back and won't let her go, Miley tricks Roxy into being her chaperone.
Guest stars: Frances Callier as Roxy, Jean Robertson as Flight Attendant
Special guest star: Selena Gomez as Mikayla, Camryn Manheim as Mikayla's manager
Billy Ray Cyrus song featured: "Ready, Set, Don't Go"

40
14
"Everybody Was Best-Friend Fighting"
Jody Margolin Hahn
Sally Lapiduss
July 29, 2007 (2007-07-29)
215
4.8[8]

Hannah is invited to play in a celebrity tennis tournament, and invites Lola (Lilly) and Mike (Oliver) to attend, but realizes she shouldn't have brought either; Jackson tricks Rico into thinking he is "cursed" by paying a psychic to tell him he is an evil boy.
Guest star: Karina Smirnoff, Michael Steger
Hannah songs featured: "Make Some Noise", "Life's What You Make It"

41
15
"Song Sung Bad"
Roger S. Christiansen
Ingrid Escajeda
August 4, 2007 (2007-08-04)
214
4.7[9]

Lilly records a song for her mother, but Miley alters her voice to make it sound better, prompting Lilly to enter in Karaoke night. At her performance, Miley sings for her using a microphone outside the room for Lilly to lip sync to, but is exposed after being scared by a spider she accidentally let loose. Meanwhile, after a faulty attempt at getting Sarah to like Rico, Jackson has to deal with her when she thinks he likes her.
Guest stars: Shanica Knowles as Amber Addison, Anna Maria Perez de Taglé as Ashley Dewitt, Morgan York as Sarah
Hannah songs featured: "I Got Nerve", "One in a Million", "Bigger Than Us", "Life's What You Make It"
Note: In this episode Lilly and Oliver are unable to sing, but in the episodes I Am Hannah, Hear Me Croak, Get Down Study-Udy-Udy and Judge Me Tender, they are shown singing.

42
16
"Me and Mr. Jonas and Mr. Jonas and Mr. Jonas"
Mark Cendrowski
Douglas Lieblein
August 17, 2007 (2007-08-17)
217
10.7[10]

When Hannah and Robbie Ray meet The Jonas Brothers, Miley becomes jealous of how much time he spends with the three boys. She and Lilly dress up as two male singers (Milo and Otis) as part of a plan to break up their "bromance". Meanwhile, Jackson tries to break the world pogo-stick record.
Guest star: Debra D. Holt
Special guest stars: The Jonas Brothers
Hannah song featured: "We Got the Party"

43
17
"Don't Stop 'Til You Get the Phone"
Rich Correll
Michael Poryes
September 21, 2007 (2007-09-21)
222
5.1[11]

In order to get the hot new Z-Phone, Miley gets Lilly to take an embarrassing paparazzi picture of Hannah to sell to a tabloid, but the picture shows a necklace that says 'Miley', so they trade the Hannah photo for a picture of "The Rock" with makeup on; Jackson gets a sunburn at a volleyball game, and doesn't want Robby to find out.
Guest stars: Tom McGowan and Romi Dames as Traci VanHorn
Special guest star: Dwayne "The Rock" Johnson as himself
Note: The episode's title is based on the song "Don't Stop 'Til You Get Enough" by Michael Jackson.

44
18
"That's What Friends Are For?"
Mark Cendrowski
Douglas Lieblein
October 19, 2007 (2007-10-19)
224
5.4[12]

Miley gets jealous when Mikayla is cast as Jake's love interest in his next movie, so she schemes to get Mikayla fired from the film; Rico bets Oliver and Jackson that they can't go as long as he can without taking a shower.
Guest star: Cody Linley, Sandy Brown, Selena Gomez
Special guest star: Camryn Manheim, Stephen Full

45
19
"Lilly's Mom Has Got It Goin' On"
Jody Margolin Hahn
Norm Gunzenhauser
November 10, 2007 (2007-11-10)
216
5.5[13]

Miley and Lilly envision becoming sisters when they notice a spark of love between Miley's dad and Lilly's mom (Heather Locklear). The girls then try to get the two to go out on a date, but when it goes wrong, the two blame each other's parent so the two girls start fighting. Meanwhile Jackson and Rico switch places to see who could last in each other's shoes.
Special guest star: Heather Locklear
Guest stars: Morgan York
Hannah song featured: "Life's What You Make It"

46
20
"I Will Always Loathe You"
Roger S. Christiansen
Michael Poryes
December 7, 2007 (2007-12-07)
218
4.4[14]

Mammaw Ruthie and Aunt Dolly return to celebrate Hannah's latest award but Dolly and Ruthie fight too much and ruin Hannah's award speech; Oliver agrees to help Rico film a commercial, but Rico can't shake his fear of being in front of a camera.
Special guest stars: Vicki Lawrence and Dolly Parton
Hannah song featured: "True Friend"

47
21
"Bye Bye Ball"
Sean Lambert
Heather Wordham
January 13, 2008 (2008-01-13)
220
4.2[15]

After Jackson ruins Miley's 'Beary Bear', Miley plots revenge and destroys his special Joey Vitolo-signed baseball. When Jackson feels guilty and fixes Beary Bear, Miley goes to great lengths to replace Jackson's ball - luckily for Miley, Joey Vitolo's daughter is a Hannah fan. Meanwhile Robbie attempts to build a bookshelf.
Guest stars: Joey Fatone and Juliette Goglia
Hannah songs featured: "Rock Star", "Life's What You Make It"

48
22
"(We're So Sorry) Uncle Earl"
Rich Correll
Robin J. Stein
March 21, 2008 (2008-03-21)
226
3.6[16]

Uncle Earl (David Koechner) arrives for a visit with the intention of becoming a rockstar; Barney Bittman (Gilbert Gottfried), a music critic renowned for his harsh criticism of popular performers, is planning on reviewing Hannah Montana.
Special guest stars: David Koechner as Uncle Earl and Gilbert Gottfried as Barney Bittman
Hannah songs featured: "The Best of Both Worlds", "Rock Star", "Nobody's Perfect".

49
23
"The Way We Almost Weren't"
Rich Correll
Andrew Green
May 4, 2008 (2008-05-04)
219
3.1[17]

While returning from Hannah's New Mexico tour, Miley nearly gets struck by lightning and dreams about how her parents first met at a diner and tries to make Robby and Miley's mom meet before she and Jackson totally disappear. Meanwhile, Lilly and Oliver get stuck to chairs, and attempt to get unstuck so they don't miss the Maroon 5 concert.
Special guest star: Brooke Shields
Hannah song featured: "Old Blue Jeans"

50
24
"You Didn't Say It Was Your Birthday"
Rich Correll
Heather Wordham
July 6, 2008 (2008-07-06)
225
5.1[17]

Miley and Jackson forget that it was their father's 40th birthday, and argue over why he is annoyed at them. When they figure it out, they go to great lengths to make it up to him. Lilly and Oliver find a chip shaped like Darth Vader and try to sell it.
Guest stars: Patrick Ryan Anderson as Todd, Adam Raque as Guy #1, Brandon Edward Gomez as Guy #2, Colton Burton as Ed, Michelle Merring as Ed's Mother, Bob Bledsoe as Frank, Kieran Newton as Jimmy
Hannah song featured: "Life's What You Make It"

51
25
"Hannah in the Streets with Diamonds"
Roger S. Christiansen
Jay J. Demopoulos &
Steven James Meyer
July 20, 2008 (2008-07-20)
228
3.8[17]

Hannah is chosen to be inducted on a walk of fame, but Miley's upset when her prime location is suddenly downgraded to make room for a star puppet, "Pancake Buffalo", with a superstar sized attitude. Meanwhile Robbie takes over Jackson's shift when he can't get his car to go.
Co-stars: Wayne Thomas Yorke as Phil, Merrit Bailey as Construction Worker, Gabriel Praddo as Astronaut Hector and Jay Jay Ellis as Little Girl
Guest stars: Michael Boatman as Randall Garrison, Edie McClurg as Cindy Merriwether, Victor Yerrid as Pancake Buffalo, Susie Geiser as Voice of Pancake Buffalo and Cornell Womack as Armand
Note: Pancake Buffalo is a parody of Lambchop and the "Hollywood Parade of Diamonds" is a parody of the Hollywood Walk of Fame.

52
26
"Yet Another Side of Me"
Shannon Flynn
Teleplay by: Andrew Green &
Sally Lapiduss
Story by: Heather Wordham
August 3, 2008 (2008-08-03)
229
4.6[17]

Hannah meets her idol, Isis, who constantly changes her image to keep things fresh. Hannah fears she will lose her audience if she doesn't follow suit, but her image makeover (Anti-Hannah) doesn't go as she imagined after a nightmare about performing for the Sunshine Girls. Meanwhile, Jackson is promised a raise by Rico, on the condition that he makes the sound of a dog when somebody say the word "dog." This makes Jackson be in a lot of trouble with an older boy, who injures him. Finally, Jackson tells Rico that if he was nicer, he would have lots of friends.
Co-stars: Matt Merchant, Brandi Cyrus, Alvin Lam, Lee Davis and Angela Trimbur
Guest stars: Rachel York, Meshach Taylor, Tiffany Thornton and Jodi Shilling
Hannah songs featured: "One in a Million" and "True Friend"
Note: Isis is a parody of Madonna. The Sunshine Girls are a parody of Girl Scouts of America and have appeared on the That's So Raven episode, Rae of Sunshine.

53
27
"The Test of My Love"
Rich Correll
Jay J. Demopoulos
August 31, 2008 (2008-08-31)
221
3.9[18]

Miley starts dating a rich boy, Trey Harris. However, Trey's parents are rude to Miley because she is from Tennessee, so she tries to impress them by pretending to be rich and fancy. Meanwhile Robbie and Jackson attempt to clean out Jackson's room.
Guest starring: Gregory Itzin as Mr. Harris, Anita Finlay as Mrs. Harris, Michael McShae as Trey Harris, Romi Dames as Traci VanHorn

54
28
"Joannie B. Goode"
Rondell Sheridan
Andrew Green
September 14, 2008 (2008-09-14)
227
4.6[19]

Oliver and Joannie start dating, and Oliver wants Miley and Lilly to be friends with her. After a sleepover, Lilly and Joannie realize they have more in common than they thought, and Miley worries that Lilly won't be her best friend anymore. Meanwhile, Jackson gets a date with Rico's cousin.
Guest stars: Hayley Chase as Joannie Palumbo and Erika Medina as Rico's sister and Natalia Baron as Teresa
Hannah song featured: "Life's What You Make It"
Note: This is one of only two episodes, the other being The Test of My Love, that do not show Miley Cyrus with the Hannah Montana wig.

55
29
"We're All on This Date Together"
Roger S. Christiansen
Steven Peterman
October 12, 2008 (2008-10-12)
230
4.4[20]

Miley's previous crush Johnny Collins (Corbin Bleu) wins a date with Hannah in a charity auction, but Hannah is forced into letting Rico join too. He wound up making the date miserable for both Johnny and Hannah. Meanwhile, Roxy's old enemy from school comes to visit, so Roxy asks Robby and Jackson to pretend to be her family.
Guest stars: Corbin Bleu as Johnny, Ray Romano as himself, Donny Osmond as himself, Sheryl Lee Ralph
Hannah song featured: "If We Were a Movie"
Note: This episode's title refers to Corbin Bleu and High School Musical's song "We're All in This Together"

tag: table

text: No Sugar, Sugar (unaired in the U.S.)[edit]

text:
No. in
series
No. in
season
Title
Directed by
Written by
Original air date
Prod.
code
Viewers
(millions)

-
30
"No Sugar, Sugar"
Art Manke
Sally Lapiduss
November 2, 2008 (2008-11-02)
(outside the U.S.)[23]
223
N/A

When Miley and Lilly suspect that Oliver has a crush on the school nurse (Rebecca Creskoff), they instead learn that Oliver has been diagnosed with diabetes, but is keeping it secret. Not knowing the whole truth about the disease, Miley overreacts to the news, and when the three attend Traci's "sweet sixteen", where a large assortment of sweets are being offered, she goes out of her way to keep Oliver from eating any of it. Meanwhile, Jackson has a new girlfriend (Katerina Graham) who is helping him earn good grades in school. When Robby finds out that she plans to break up with him, he does everything he can to save their relationship.
Guest stars: Rebecca Creskoff as School Nurse Carol, Shanica Knowles as Amber Addison, Anna Maria Perez de Taglé as Ashley Dewitt, Romi Dames as Traci VanHorn, Katerina Graham as Allison, Jackson's Girlfriend
Note: This episode was set to air in the U.S. on November 2, 2008 but Disney pulled the episode from the schedule after it was previewed by parents in an on-demand version; according to one of the parents, inaccuracies regarding the portrayal of diabetes were at the heart of their objections, adding that given Hannah Montana's huge influence over young viewers, correct information about the disease needed to be given. According to Mitchel Musso, the episode was re-written, re-shot, and was to be added to the third season of the show.[21] The revised episode, called "Uptight (Oliver's Alright)" aired on Disney Channel on September 20, 2009.[22]


document_title: Legal status of tattooing in the United States

question_text: how old do you have to be in south carolina to get a tattoo

text: In the United States, there is no federal law regulating the practice of tattooing. However, all 50 states and the District of Columbia have statutory laws requiring a person receiving a tattoo be 18 years or older. This is partially based on the legal principle that a minor cannot enter into a legal contract or otherwise render informed consent for a procedure. Most states permit a person under the age of 18 to receive a tattoo with permission of a parent or guardian, but some states outright prohibit tattooing under a certain age regardless of permission, with the exception of medical necessity (such as markings placed for radiation therapy).

text: In all jurisdictions, individual tattooists may also choose to place additional restrictions based on their own moral feelings, such as refusing any clients under a specific age even with parental consent despite it being legal, or limiting the type and/or location of where they are willing to tattoo (such as refusing any work around intimate parts of the body). They may additionally refuse to perform specific artwork, including if they merely find it inappropriate or offensive, or refuse to work on a client that they suspect may be intoxicated. Artists sometimes claim their personal business restrictions are a matter of law even when it is not true, so as to avoid arguments with clients.

text:
Legal Restrictions on Tattooing & Body Modification by State

State
Minimum Age (with parent/guardian consent)
Form of Parent/Guardian Consent
Notes & Exceptions
Intoxicated/Impaired Individuals
Area of Law/Type of Penalty
Licensing & Regulation
Relevant Statute(s) and Rules

Alabama
none specified[1]
informed written consent, signed in presence of the artist/service provider or their agent[1][2]
Ear piercing exempt from Alabama body art laws & rules.[2][3]
cannot be tattooed, branded, or pierced[1][2]
Violations of Alabama Tattoo & Body Piercing laws are a class c misdemeanor, punishable by a fine of up to $100 and/or up to 90 days imprisonment for each violation.[4]
Alabama's Department of Public Health licenses Tattoo, body piercing, & body art facilities, and sets standards for their operation.[5]
Individual tattoo artists, piercers, etc. require a permit.[2]

Ala. Code § 22-1-17A[3][6]
State Board of Health rules on Body Art Practices and Facilities.[2]

Alaska
18 (piercing excepted)[7]
parent/guardian must both give written consent and be present during the procedure[7]
Minors may be pierced with parental consent [7]
no restriction[8]

Alaska Stat. § 08.13.217[7]

Arizona
none specified[9]
parent/guardian must be physically present[9]
Minors can have their ears pierced with the written or verbal consent of a parent/guardian, can have procedures prescribed by a health care provider.[9]
no restriction[9]
Violations are a class 6 felony.[9]
There are no health regulations for tattoo shops in Arizona. [10]
Tattoos. Ariz. Rev. Stat. § 13-3721[9]

Arkansas
16[11]
parent/guardian must both give written consent and be physically present[12]
none specified[12]
cannot be tattooed, branded, or pierced.[12]

Ark. Stat. Ann. §§ 20-27-1501 et seq.[12]

California
18 (piercing excepted)[13][14]
parent/guardian must be present during procedure
Minors may have their ears pierced with parental consent.[15] They may be pierced elsewhere with parental consent, but not on their genitals or nipples. Permanent cosmetics are permitted on nipples, when done by a cosmetic technician and with parental consent.[14]
no restriction

Body Art. Cal. Health & Safety Code § 119300 to 119328[6][15]
Cal. Penal Code 653[13]

Colorado
18 Express written consent of parent or guardian[16]
parent/guardian must be present during procedure
Persons who are "noticeably impaired" cannot have body art procedures[16]

Body Artists. Colo. Rev. Stat. § 25-4-2101 to 2103[6]

Connecticut
none specified
permission of parent or guardian[17][18]
Minors may have their ears pierced without parental consent[17]
Tattooing may only be performed by physicians, or by registered nurses & technicians working under the supervision of a physician.[18]

no restrictions

Conn. Gen. Stat. §19a-92a,[6][18]
Conn. Gen. Stat. §19a-92g[6][17]

District of Columbia
18 (ear piercing excepted)[19]
written consent (for ear piercing)[19]
minors may have their ears pierced with written parental consent[19]
no restrictions[19]

Body Artists. DC Code § 47-2853.76d[6][19]

Delaware
18[20]
notarized written consent to the specific procedure[20]
none specified[20]
cannot be tattooed, branded, or body pierced[20]

Del. Code Ann. Title 11, Ch 5 §1114(a)[6][20]
Del. Code Ann. Title 16, Ch 2 §122(3)(w)[6]

Florida
16[21]
Must be accompanied by parent or guardian who can show proof of guardianship, both parent and minor must present photo ID, and a consent form must be notarized.[21]
for medical or dental purposes by a licensed physician or dentist[21]
no restriction

Fla. Stat. § 381.00787[6]
Fla. Stat. §381.0775 et seq.[6] Fla. Stat. §381.075[6]

Georgia
18 (body piercing excepted)[22]
For body piercing: prior written consent of parent/guardian[23]
Minors may have their ears pierced without parental consent[23]
Minors may be body pierced with written parental consent[23]
Physicians and Osteopaths or technicians working under their direct supervision can give minors tattoos or produce scars for "medical or cosmetic purposes."[22]
No one can be tattooed within an inch of their eye socket.[24]

no restrictions

Ga. Code § 31-40-1 to 31-40-10[6]
Ga. Code § 16-12-5[6]
Ga. Code § 16-5-71.1[6]

Hawaii
none specified[25]
written consent of parent/guardian[25]

Hawaii Rev. Stat. § 321-13[6]
Hawaii Rev. Stat. § 321-379[6]

Idaho
18[26]
Written informed consent of parent/guardian, executed in the presence of the person performing the procedure, or their agent/employee.[26]
Minors can have their ears pierced without parental consent.[6]
Piercing for medical procedures exempt.[6]

no restrictions

Idaho Code § 18-1523 (2004)[6]

Illinois
18 (body piercings excepted)[27]
Written consent of parent/guardian (for body piercings)[27]
Minors cannot be present in places where tattooing or body piercing is done except in the presence of a parent/guardian.[27]
Minors can have their ears pierced without parent/guardian consent.[27]

no restrictions

Ill. Stat. 720 §5/12-10.1[6]
Ill. Stat. 410 §54/1 t0 54/999[6]

Indiana
none specified[28]
Parent/guardian must both be present during the procedure and provide written permission.[28]
Minors may have their ears pierced without parental consent.[28]
no restrictions

Ind. Code Ann. §35-42-2-7[6][28]
Ind. Code Ann. §16-19-3-4.1[6][29]

Iowa
18[30]
n/a - minors cannot be tattooed[30]
Body piercing is not regulated by state law in Iowa, however county or city laws may regulate it.[31]
no restrictions

Iowa Code §135.37[6]
Iowa Code §135.37[6]

Kansas
16[32]
Parent/guardian must give written consent, written consent must be notarized, and the parent/guardian must be present during the procedure.[32]
Minors may have their ears pierced[33]
no restrictions

Kan. Stat. Ann. §65-1953[6]
Kan. Stat. Ann. §65-1940 to 65-1954[6]

Kentucky
16
Parent/guardian must give written, notarized consent.[34]
none (ear piercing also requires written, notarized consent).[35]

Ky. Rev. Stat. §211.760[6]
Ky. Rev. Stat. §194A.050; 211.760[6]

Louisiana
16
Parent or guardian must consent, and their presence during the procedure is required for tattoos, but not for body piercings.[36]

no restrictions

La. Rev. Stat. Ann. §14:93.2[6]
La. Rev. Stat. Ann. § 40:2831 et seq.[6]

Maine
18 (piercings excepted)[37]
For body piercings: prior legal consent of parent/guardian.[38]
Maine law does not require parent/guardian consent for ear piercing[39]
no restrictions

Me. Rev. Stat. Ann. Title 32 § 4201-4329[6]

Maryland
none specified[40]
written consent, which must be retained for 3 years.
Piercing of the ear lobe is exempt[41]
no restriction
Health Department Regulations
A license is not required, but any person performing tattooing or piercing must comply with all the relevant health code regulations[40]
COMAR 10.06.01.02 and 10.06.01.06

Massachusetts
18 (except body piercing other than genitalia)[42]
Minors cannot receive tattoo, branding, or scarification at all. For piercing of areas other than the genitalia, a parent may provide identification and sign the consent document.[42]
Physicians performing for treatment reasons and ear piercing are exempt from regulation.[42]
no restriction
County Health Department regulates body art, but all follow a model regulation set by the state.
Artists must have a permit, and establishments are subject to following specific health department regulations[42]
Model Regulations for Body Art Establishments[42]

Michigan
none specified[43]
Written, informed consent of parent/guardian. Must be executed (signed) in the presences of the person performing the procedure, or their employee.[43]

cannot be tattooed, branded, or body pierced.[43]

Mich. Comp. Laws § 333.13101 to 333.13112[44]

Minnesota
18 (piercings excepted)[45]
For piercings: presence of parent/guardian and a consent form are both required.[45]
Minors cannot be tattooed. They can be body pierced, but not in the nipples or genitals. Branding, scarification, suspension, subdermal implantation, microdermal, and tongue bifurcation are also prohibited for minors.[45]
cannot have any body art procedures.[45]

Minnesota Statutes 146B.07[45]

Mississippi
18
n/a - minors cannot be tattooed
piercing also prohibited except for the outer perimeter or lobe of the ear.
no restriction

Miss.Code Ann. §73-61

Missouri
none specified[46]
For both piercings and tattoos, parent/guardian must sign written consent in the presence of the person performing the procedure, or their employee.[46]

cannot be tattooed, branded or body pierced.[46]
violations are a misdemeanor, punishable with a fine of up to $500 (more for repeat offenses)[46]
The state director of the division of professional registration licenses all body artists, and sets rules & regulations for the operation of body art establishments.[47]
Mo. Rev. Stat. §324.520[46]

Montana
none specified[48]
Parent or guardian must give "explicit, in-person" consent.[48] Montana administrative rules also require that the parent/guardian be present throughout the procedure.[49]

cannot be tattooed or body pierced.[49]
A person who tattoos or body pierces a minor without parent/guardian consent is guilty of Unlawful transactions with children, punishable by a fine of up to $500 or six months in county jail, or both.[48]
Other violations of Montana body art laws are a misdemeanor, with punishments ranging from a fine of $50–100 for a first offense to $300 and/or 90 days in county jail for third and subsequent offense.[50]

Montana's Department of Health and Safety licenses and regulates body art establishments.[51] Local health boards may establish their own licensing and regulatory schemes in lieu of the state department's.[52]
Mont. Code Ann. §45-5-623[48]
Mont. Code Ann. §50-48-101 to 110[53]
Mont. Code Ann. §50-48-201 to 209[54]

Nebraska
none specified[55]
written consent, must be present during procedure
Piercing does not include the external parts of the ear[56]
No restrictions

Nebraska Revised Statute 38-1008, 38-1009, 38-1010, 38-1011, 38-1060, 38-10,165

Nevada
n/a[6]
n/a[6]
Nevada state law does not regulate tattoos, piercings, or other body art. Regional health districts may regulate the practice. The southern Nevada Health District, for example, does not allow minors below the age of 14 to be tattooed, and requires a parent or guardian to provide written consent and be present during the procedure for 14- to 18-year-olds. The southern Nevada district also bans tattoos on those who are under the influence of drugs or alcohol.[57]
n/a[6]

n/a[6]

New Hampshire
18 (piercings excepted)[58]
For piercings: parent/guardian must both sign written consent and be present during the procedure.
Minors cannot be tattooed or branded. They may be pierced with parent/guardian consent.[58] Minors may have their ears pierced without parent/guardian consent.[59]
no restrictions

N.H. Rev. Stat. Ann. § 314[6]

New Jersey
none specified[60]
written permission of parent/guardian is required for tattooing and body piercing.[60]
Parent/guardian must be present and sign written consent for ear piercings as well as for body piercing. Minors cannot have genital piercings even with parent/guardian consent.[61]
no restrictions
no restrictions
no restrictions
N.J. Stat. Ann. §2C:40-21
N.J.A.C. 8:27-1 et seq.
N.J. Stat. Ann. §26-1A-7[6]

New Mexico
none specified[62]
Written consent and presence during the procedure.
Medical procedures by physicians and ear piercing are exempt[63]
no restrictions
Administrative Regulations set by the Board of Barbers and Cosmetologists
All body artists are required to be licensed through the state, and are subject to regulations from the Board
Body Art Safe Practices Act. N.M. Stat. Ann. § 61-17B et seq.,[63] N.M. Administrative Code 16.36 et seq.[62]

New York
18 (piercings excepted) [64]
Minors cannot be tattooed with parent/guardian consent. For piercings: parent/guardian must give written consent, signed in presence of the body artist or body art establishment owner.[65]
Written parental consent is not required for ear piercings.[66]
no restrictions

New York Public Health Law, Article 4-A[6][65]
N.Y. Public Health Law §460-466[6]
N.Y. Penal Law § 260.21[6]

North Carolina
18 (piercings excepted)[67]
Minors cannot be tattooed, even with parent/guardian consent. "Prior consent" of parent/guardian is required for body piercings.[67]
Minors may have their ears pierced without parental consent.[67]
no restrictions

N.C. Gen. Stat. § 130A-283[68]
N.C. Gen. Stat. § 14-400[69]

North Dakota
none specified[70]
Parent/guardian must be present during the procedure and give written consent.[70]

cannot get tattoos or other body art[71]

N.D. Code §23-01-35[72]
N.D. Code §12.1-31-13[6][70]

Ohio
none specified[73]
Parent/guardian must both sign a consent form and "appear in person at the business at the time the procedure is performed."[73]
none - parent/guardian consent and presence is also required for ear piercings.[73]
no restrictions

Ohio Rev. Code Ann. §3730.01 to 3730.99[6][73]

Oklahoma
18 (piercings excepted)[74]
Minors cannot be tattooed, even with parent/guardian consent. For piercings: parent/guardian must both give written consent and be present during the procedure.[74]
Ear piercing is not governed/restricted by Oklahoma law.[74]
Scleral tattooing is illegal.[74]

cannot be tattooed.[74]

Okla. Stat. Title 21 §842.1, 842.2, 842.3[6]

Oregon
18 (piercings excepted)[75]
For piercings: parent/guardian must give written consent and present proof of identity.[76][77]
Minors can only be tattooed with the authorization of a physician.[75]
Scarification and dermal implants are prohibited[78]
Persons with sunburns or skin diseases or disorders cannot be tattooed or pierced.[75][77]
Minors cannot be pierced on the genitals or nipples, even with parent/guardian consent.[76]
Piercing on testes, deep shaft (corpus cavernosa), uvula, eyelids and sub-clavicle are all prohibited.[77]

cannot be tattooed or pierced.[75][77]
Violations of Oregon body art laws are a misdemeanor.[79]
Violations of Health Licensing Office rules are fined (various amounts).[80]

Both body artists and body art establishments are licensed by the Oregon Health Licensing Office.[81] With the assistance of a Board of Body Art practitioners, the Health Licensing Office also sets detailed rules and regulations for body art.[82]
Or. Rev. Stat. § 690.350 et seq
Or. Rev. Stat. § 690.401 to 410
Or. Rev. Stat. § 679.500[6]
Health Licensing Office Rules, especially Divisions 900, 905, 915 & 920[82]

Pennsylvania
none specified[83]
parent/guardian must both give consent and be present during the procedure.[83]

no restrictions

Pa. Cons. Stat. Title 18 § 6311[6][83]

Rhode Island
18 (piercings excepted)[84][85]
Minors cannot be tattooed.[84] For piercings: parent/guardian must both give consent and be present for the procedure.[85]

no restrictions
Tattooing a minor is a criminal offense (misdemeanor), maximum fine $300[84]
Tattooing and body art are regulated by the department of health, artists must be registered.[85]
RI Gen L § 23-1-39[85]
RI Gen L § 11-9-15[84]

South Carolina
18 (piercings excepted)[86][87]
Minors cannot be tattooed.[86] For piercings: parent/guardian must either give written, notarized consent or be present during the procedure.[87]
Head, face, and neck tattoos are illegal.[86]
cannot be tattooed or body pierced[86][88]
Under the Health Code, persons violating restrictions on tattooing and body piercing are guilty of a misdemeanor. Upon conviction, they may be fined up to $2500 or imprisoned for a year, or both.[86][87]
Tattoo and body piercing facilities are regulated by the Department of Health and Environmental Control. Tattoo facilities are licensed, body piercing facilities require a permit, and artists must be registered[89][90]
S.C. Code § 44-32-10 to 44-32-120[88]
S.C. Code § 44-34-10 to 44-34-110[91]

South Dakota
none specified[92]
Parent/guardian must sign a consent form.[92]

cannot be tattooed or pierced[93][94]
Tattooing a minor is a class 2 misdemeanor.[95]
Tattooing and Body Piercing are governed by Department of Health rules.[96] Municipalities may set stricter regulations, and have the authority to license body artists.[95]
S.D. Codified Laws Ann. §26-10-19[92]
S.D. Laws § 9-34-17[95]

Tennessee
18 (piercings excepted)[97][98]
For tattoos that cover an existing tattoo (see Notes & Exceptions): Parent/Guardian must be present during the procedure.[97]
For piercings: Parent/Guardian must give written consent, be present during the procedure.[98]

Minors over the age of sixteen may be tattooed to cover up an existing tattoo, with parent/guardian consent.[97]

Minors who lie about their age to be tattooed are guilty of a "delinquent act," are required to pay a fine of $50–$250 and serve at least 20 hours of community service.[97]
Tattooing a minor is a class a misdemeanor,[97] breach of body piercing law is a class b misdemeanor.[99]

Tattoo artists and body piercers are licensed by the state department of health, tattoo shops require a certificate from the local health department.[100][101]
Tenn. Code §§ 62-38-201-310[102]

Texas
18 (piercings excepted)[103][104]
For body piercings and for covering existing tattoos (see Notes & Exceptions): Parent/guardian must be present during procedure, sign an affidavit[103][104]
Ear piercing is exempt from body piercing statutes[105]
Minors may, with parent/guardian consent, be tattooed to cover up an existing tattoo that has offensive, gang-related, or drug-related content, or "other words, symbols, or markings that the person's parent or guardian considers would be in the best interest of the person to cover"[103]
Tongue splitting prohibited.[106]

Cannot be tattooed or pierced.[103][107]
Misrepresenting one's age to get a tattoo, or to get a piercing without parental consent, is a class B misdemeanor[103][104]
Violations of Texas tattooing & body piercing statute are a Class A misdemeanor, with each day of violation counting as a separate offense.[108]
Health Commissioner can impose a fine of up to $5000 on artists & shops for each violation[109]

Tattoo artists and body piercers must be registered with the Texas Department of Health[110] Tattoo and body piercing shops must be licensed[111]
Texas Health and Safety Code Ann. §146[112]

Utah
none specified[113]
Parent/guardian must be present during the procedure, give written permission, and provide proof of identity.[113]
Parental consent not required by law for ear piercing[113]

Tattooing or body piercing a minor is a class b misdemeanor, shops can be fined up to $1000 for each violation.[113]

Utah Code Ann. §76-10-2201[6]

Vermont
none specified[114]

Tattooists and body piercers must be registered.[114]
Vt. Stat. Ann. Title 26 §4101 to 4109[6][115]

Virginia
none specified[116]
Parent/Guardian must be present during the procedure.[116]
Virginia law does not limit minors' ability to have their ears pierced.[116]

Tattooing or body piercing a minor is a class 1 misdemeanor[116]
Tattoo artists and body piercers, as well as the operators of tattoo and body piercing establishments, are licensed by the state.[117][118]
Civic/local governments are empowered to regulate tattoo and body piercing establishments.[119]

Va. Code §54.1-700 et seq.
Va. Code §15.2-912
Va. Code § 18.2-371.3.[6]

Washington
18 (piercings excepted)[120]

cannot have tattoos, body piercings, or other body art.[121]

Wash. Code §26.28.085[120]
Wash. Code § 18.300[122]
Wash. Code § 246-145-001 to 060[123]
Wash. Code §70.54[124]

West Virginia
none specified[125]
parent/guardian must give written consent[125]

All persons receiving a tattoo must attest they are not under the influence of drugs or alcohol.[125]

Tattoo shop owners and body piercing studios must register with local board of health, and must be registered as a business with the state[126][127][128]
W. Va. Code §16-37
W. Va. Code §16-38[129]

Wisconsin
18[130]
n/a (tattooing not permitted under 18)
Physicians in the course of professional practice are exempt
no restriction
Tattooing a minor or even offering to do so is subject to a fine of up to $200
Artists must be satisfy training requirements and obtain a license from the health department. Establishments are subject to inspection and licensing[131]
Wisconsin Statutes & Annotations 948.70 and 252.235

Wyoming
none specified[132]
Verbal consent, presence during procedure.[132]
Procedures performed under the supervision of a licensed physician, and piercing of the ear, do not count as body art for this law.
no restriction[132]
Misdemeanor criminal offense, punishable by fine and prison time[132]

Wyoming Statute §14-3-107[132]