Electric Charge

Electric charge is the physical property of matter that causes it to experience a force when close to other electrically charged matter. There are two types of electric charges, called positive and negative. Positively charged substances are repelled from other positively charged substances, but attracted to negatively charged substances; negatively charged substances are repelled from negative and attracted to positive. An object will be negatively charged if it has an excess of electrons, and will otherwise be positively charged or uncharged. The SI unit of electric charge is the coulomb (C).