What we describe as electricity concerns the behavior of atoms that have become, for whatever reason, unbalanced or electrified. Obviously, there is more to atomic structure than what has been outlined so far. However, understanding a little about atomic structure and behavior can help the technician “see” electricity in a different way when it comes to figuring out failures in electrical circuits. Here is a summary of what we have said about atomic structure so far:
• In the center of every atom is a nucleus.
• The nucleus is made up of positively charged matter called protons.
• The nucleus contains matter with no charge, called neutrons.
• Negatively charged particles, called electrons, are orbiting each atomic nucleus.
• Electrons orbit the nucleus in concentric paths called shells.
• All electrons are alike.
• All protons are alike.
• Every chemical element has a distinct identity and is made up of distinct atoms. That is, each has a different number of protons and electrons.
• In an electrically balanced atom, the number of protons equals the number of electrons. This means that the atom is in what is described as a neutral state of electrical charge.
• An atom with either a deficit or an excess of electrons is known as an ion.
• Charge can move from one point to another.
• Like charges repel.
• Unlike charges attract.
• Electrons (negative charge) are held in their orbital shells by the nucleus (positive charge) of an atom.
• Electrons are prevented from colliding with each other because they all have similar negative charges that tend to repel each other.
• A molecule is a chemically bonded union of two or more atoms.
• A compound is a chemically bonded union of atoms of two or more dissimilar elements.
The preceding statements are reinforced as we continue to study electricity and magnetism throughout this chapter. In fact, they are repeated many times, although in slightly different formats.