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'''Charge''' is the [[fundamental]] property of any [[matter]] that exhibit electrostatic [[attraction]] or repulsion over other matter. Electric charge is a characteristic property of many [http://en.wikipedia.org/wiki/Charged_particle subatomic particles]. The charges of free-standing [[particles]] are integer multiples of the elementary charge e; we say that electric charge is ''quantized''. [http://en.wikipedia.org/wiki/Michael_Faraday Michael Faraday], in his [http://en.wikipedia.org/wiki/Electrolysis electrolysis] [[experiments]], was the first to note the discrete [[nature]] of electric charge. [http://en.wikipedia.org/wiki/Robert_Millikan Robert Millikan]'s oil-drop [[experiment]] [[demonstrated]] this [[fact]] directly, and measured the elementary charge.

'''Charge''' is the [[fundamental]] property of any [[matter]] that exhibit electrostatic [[attraction]] or repulsion over other matter. Electric charge is a characteristic property of many [https://en.wikipedia.org/wiki/Charged_particle subatomic particles]. The charges of free-standing [[particles]] are integer multiples of the elementary charge e; we say that electric charge is ''quantized''. [https://en.wikipedia.org/wiki/Michael_Faraday Michael Faraday], in his [https://en.wikipedia.org/wiki/Electrolysis electrolysis] [[experiments]], was the first to note the discrete [[nature]] of electric charge. [https://en.wikipedia.org/wiki/Robert_Millikan Robert Millikan]'s oil-drop [[experiment]] [[demonstrated]] this [[fact]] directly, and measured the elementary charge.

By [[convention]], the charge of an [[electron]] is −1, while that of a [http://en.wikipedia.org/wiki/Proton proton] is +1. Charged particles whose charges have the same sign repel one another, and [[particles]] whose charges have [[different]] signs [[attract]]. [http://en.wikipedia.org/wiki/Coulomb%27s_law Coulomb's law] quantifies the electrostatic [[force]] between two [[particles]] by asserting that the [[force]] is [[proportional]] to the product of their charges, and [http://en.wikipedia.org/wiki/Inverse_square inversely proportional to the square] of the distance between them.

By [[convention]], the charge of an [[electron]] is −1, while that of a [https://en.wikipedia.org/wiki/Proton proton] is +1. Charged particles whose charges have the same sign repel one another, and [[particles]] whose charges have [[different]] signs [[attract]]. [https://en.wikipedia.org/wiki/Coulomb%27s_law Coulomb's law] quantifies the electrostatic [[force]] between two [[particles]] by asserting that the [[force]] is [[proportional]] to the product of their charges, and [https://en.wikipedia.org/wiki/Inverse_square inversely proportional to the square] of the distance between them.

The charge of an [http://en.wikipedia.org/wiki/Antiparticle antiparticle] [[equals]] that of the corresponding [[particle]], but with opposite sign. [http://en.wikipedia.org/wiki/Quark Quarks] have [[fraction]]al charges of either −1⁄3 or +2⁄3, but free-standing quarks have never been observed (the [[theoretical]] reason for this [[fact]] is [http://en.wikipedia.org/wiki/Asymptotic_freedom asymptotic freedom)].

The charge of an [https://en.wikipedia.org/wiki/Antiparticle antiparticle] [[equals]] that of the corresponding [[particle]], but with opposite sign. [https://en.wikipedia.org/wiki/Quark Quarks] have [[fraction]]al charges of either −1⁄3 or +2⁄3, but free-standing quarks have never been observed (the [[theoretical]] reason for this [[fact]] is [https://en.wikipedia.org/wiki/Asymptotic_freedom asymptotic freedom)].

The electric charge of a [http://en.wikipedia.org/wiki/Macroscopic macroscopic] object is the sum of the electric charges of the particles that make it up. This charge is often zero, because [[matter]] is made of [[atoms]], and atoms all have [[equal]] numbers of [http://en.wikipedia.org/wiki/Proton protons] and [[electrons]]. More generally, in every [[molecule]], the [[number]] of [http://en.wikipedia.org/wiki/Anion anions] (negatively charged atoms) equals the number of [http://en.wikipedia.org/wiki/Cation cations] (positively charged atoms). When the net electric charge is non-zero and motionless, the [[phenomenon]] is known as [http://en.wikipedia.org/wiki/Static_electricity static electricity]. Even when the net charge is zero, it can be distributed non-uniformly (e.g., due to an external [http://en.wikipedia.org/wiki/Electric_field electric field] or to molecular [[motion]]), in which case the [[material]] is said to be [[polarized]]. The charge due to [[polarization]] is known as [http://en.wikipedia.org/wiki/Bound_charge bound charge], while the excess charge brought from outside is called free charge. The motion of charged particles (especially the motion of electrons in metals) in a given direction is known as [http://en.wikipedia.org/wiki/Electric_current electric current].[http://en.wikipedia.org/wiki/Electric_charge]

The electric charge of a [https://en.wikipedia.org/wiki/Macroscopic macroscopic] object is the sum of the electric charges of the particles that make it up. This charge is often zero, because [[matter]] is made of [[atoms]], and atoms all have [[equal]] numbers of [https://en.wikipedia.org/wiki/Proton protons] and [[electrons]]. More generally, in every [[molecule]], the [[number]] of [https://en.wikipedia.org/wiki/Anion anions] (negatively charged atoms) equals the number of [https://en.wikipedia.org/wiki/Cation cations] (positively charged atoms). When the net electric charge is non-zero and motionless, the [[phenomenon]] is known as [https://en.wikipedia.org/wiki/Static_electricity static electricity]. Even when the net charge is zero, it can be distributed non-uniformly (e.g., due to an external [https://en.wikipedia.org/wiki/Electric_field electric field] or to molecular [[motion]]), in which case the [[material]] is said to be [[polarized]]. The charge due to [[polarization]] is known as [https://en.wikipedia.org/wiki/Bound_charge bound charge], while the excess charge brought from outside is called free charge. The motion of charged particles (especially the motion of electrons in metals) in a given direction is known as [https://en.wikipedia.org/wiki/Electric_current electric current].[https://en.wikipedia.org/wiki/Electric_charge]

[[Category: Physics]]

[[Category: Physics]]