当气球与毛衣摩擦时，气球会充电。由于这种电荷，气球可以粘在墙壁上，但是当放置在另一个也被擦过的气球旁边时，第一个气球将以相反的方向飞行。这种现象是称为电荷的物质性质的结果。电荷产生电场：带电粒子周围的空间区域或其他带电粒子或物体感觉到力的物体。电荷可以是正电荷或负电荷，是导致两个物体吸引或排斥的物质的特性。如果物体带相反电荷（正负），它们会吸引;如果他们的收费相似（正面或负面），他们将会击退。电荷单位是库仑，其定义为1安培的电流在1秒内传输的电量。原子是物质的基本单位，由三种类型的粒子组成：电子，中子和质子。电子和质子本身是带电的并且分别具有负电荷和正电荷。中子不带电。许多物体是电中性的并且总净电荷为0.如果电子或质子过量，从而产生不为零的净电荷，则物体被认为是带电的。量化电荷的一种方法是使用常数e = 1.602 * 10-19 Coulombs。电子是负电荷的最小量，其电荷为-1.602 * 10-19库仑。质子是最小量的正电荷，其电荷为+ 1.602 * 10-19库仑。因此，10个电子的电荷为-10 e，10个质子的电荷为+ 10 e。电荷相互吸引或相互排斥，因为它们相互施加力。两个电点电荷之间的力 – 理想化的电荷集中在空间中的一个点 – 由库仑定律描述。库仑定律表明，两个点电荷之间的力的强度或大小与电荷的大小成比例，并且与两个电荷之间的距离成反比。
When a balloon is rubbed against a sweater, the balloon becomes charged. Because of this charge, the balloon can stick to walls, but when placed beside another balloon that has also been rubbed, the first balloon will fly in the opposite direction. This phenomenon is the result of a property of matter called electric charge. Electric charges produce electric fields: regions of space around electrically charged particles or objects in which other electrically charged particles or objects would feel force. An electric charge, which can be either positive or negative, is a property of matter that causes two objects to attract or repel. If the objects are oppositely charged (positive-negative), they will attract; if they are similarly charged (positive-positive or negative-negative), they will repel. The unit of electric charge is the Coulomb, which is defined as the amount of electricity that is conveyed by an electrical current of 1 Ampere in 1 second. Atoms, which are the basic units of matter, are made of three types of particles: electrons, neutrons, and protons. Electrons and protons themselves are electrically charged and have negative and positive charge, respectively. A neutron is not electrically charged. Many objects are electrically neutral and have a total net charge of 0. If there is an excess of either electrons or protons, thus yielding a net charge that is not zero, the objects are considered charged. One way to quantify electrical charge is by using the constant e = 1.602 *10-19 Coulombs. An electron, which is the smallest quantity of negative electrical charge, has a charge of -1.602 *10-19 Coulombs. A proton, which is the smallest quantity of positive electrical charge, has a charge of +1.602 *10-19 Coulombs. Thus, 10 electrons would have a charge of -10 e, and 10 protons would have a charge of +10 e. Electric charges attract or repel each other because they exert forces on each other. The force between two electric point charges—idealized charges that are concentrated at one point in space—is described by Coulomb’s law. Coulomb’s law states that the strength, or magnitude, of the force between two point charges is proportional to the magnitudes of the charges, and inversely proportional to the distance between the two charges.