The **coulomb** (symbol: C) is the SI unit of electric charge. It is named after Charles-Augustin de Coulomb [1] (1736 to 1806).

## DefinitionEdit

1 coulomb is the amount of electric charge carried by a current of 1 ampere flowing for 1 second.

- $ C = A \cdot s $

## ExplanationEdit

The coulomb could in principle be defined in terms of the charge of an electron or elementary charge. Since the values of the Josephson constant [2] (CIPM (1988) Recommendation 1, PV 56; 19) and von Klitzing constant [3] (CIPM (1988), Recommendation 2, PV 56; 20) constants have been given conventional values (K_{J} ≡ 4.835 979^{14} Hz/V and R_{K} ≡ 2.581 280 7×10^{4}Ω), it is possible to combine these values to form an alternative (not yet official) definition of the coulomb. A coulomb is then equal to exactly 6.241 509 629 152 65 x 10^{18} elementary charges. Combined with the current definition of the ampere, this proposed definition would make the kilogram a derived unit.

## SI multiplesEdit

Multiple | Name | Symbol | Multiple | Name | Symbol |
---|---|---|---|---|---|

10^{0}
| coulomb | C | |||

10^{1}
| decacoulomb | daC | 10^{−1}
| decicoulomb | dC |

10^{2}
| hectocoulomb | hC | 10^{−2}
| centicoulomb | cC |

10^{3}
| kilocoulomb | kC | 10^{−3}
| millicoulomb | mC |

10^{6}
| megacoulomb | MC | 10^{−6}
| microcoulomb | µC |

10^{9}
| gigacoulomb | GC | 10^{−9}
| nanocoulomb | nC |

10^{12}
| teracoulomb | TC | 10^{−12}
| picocoulomb | pC |

10^{15}
| petacoulomb | PC | 10^{−15}
| femtocoulomb | fC |

10^{18}
| exacoulomb | EC | 10^{−18}
| attocoulomb | aC |

10^{21}
| zettacoulomb | ZC | 10^{−21}
| zeptocoulomb | zC |

## Conversions Edit

- One mole of electrons (approximately 6.022 10
^{23}, or Avogadro's number [4]) is known as a faraday (actually -1 faraday, since electrons are negatively charged). One faraday equals 96.485 341 5 kC (the Faraday constant [5]). In terms of Avogadro's number (N_{A}), one coulomb is equal to approximately 1.036 x N_{A}x 10^{−5}elementary charges.

- one ampere-hour = 3600 C

- The elementary charge is approximately 160.2176 zC.

- One statcoulomb (statC), the CGS electrostatic unit of charge (esu), is approximately 3.3356 x 10
^{−10}C or about 1/3 nC.

## See also Edit

- Coulomb's law [6]
- Current (electricity)
- Faraday constant
- Quantity of electricity
- SI
- Ampere

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