After carefully studying the atomic structure, has led you on conceptual knowledge that is still associated with prior knowledge, ie electric charge. Electric charge is a term that is quite important in the world of electricity. Electric charge is the physical properties of each object. According to Benjamin Franklin, the electrical charge can be divided into two, namely a positive charge and a negative charge.
All good things solid, gas and liquid, composed of tiny particles called molecules. The molecules themselves are formed by particles smaller again called atoms. Object in which the molecules are composed of the same atoms, commonly referred to as an element. When the atoms that make up molecules together, called the mix. For example, the structure of the hydrogen atom consists of one proton and one electron, oxygen atom consists of eight protons, eight neutrons and eight electrons. Figure 1.6 shows the structure of hydrogen and oxygen atoms.
Figure 1.6 The structure of the hydrogen atom (a) and oxygen atoms (b)
The water formed from water molecules. One molecule of water (H2O) is composed of two elements, atoms, namely two hydrogen atoms (H) and one atom of oxygen (O). Arrangement of water molecules is shown in Figure 1.7.
Figure 1.7 Composition of water molecules (H20)
Electric charge is the nature of which is owned by some subatomic particles, which will determine the electromagnetic interaction. Electric charge of an object can be influenced and generate an electromagnetic field. Interaction between the movement of electrical charges and electromagnetic fields are a source of electromagnetic force. Atoms lose or gain additional electrons are considered unstable. An excess of electrons in an atom produces a negative charge.
Shortage of electrons in an atom would produce a positive charge. A different electrical charge will react in different ways. Two negatively charged particles would repel each other, as well as two positive bemuatan particles. From the experiments it can be proved that an electric charge can be quantified, the value of the charge of the electron at 1,602 × 10-19. Because it is commonly abbreviated negatively charged with -e, and for proton shortened to + e because of the positively charged.