1. An ion of an atom is one in which the number of protons and electrons is not the same. If there are more protons than electrons, an atomic ion has a positive charge and is called a cation. If there are more electrons than protons, the ion has a negative charge and is called an anion.
2. Such bonds are created when the outermost electrons of one atom (such as sodium) are transferred permanently to another atom (such as chlorine). The atom that has lost an electron becomes a positively charged ion (called a cation), while the atom that picks up the extra electron becomes a negatively charged ion (called an anion).
3. For a chlorine atom to become a chloride ion, it must gain an electron. The chloride ion has a negative charge and is written as Cl-. Chlorine gains an electron because it has seven valence electrons, and to be a full octet, it gains an electron. A chloride ion is called an anion. Its electron configuration is 1s2 2s2 2p6 3s2 3p6.
4.Ionic bonds are also formed when there is a large electronegativity difference between two atoms. This difference causes an unequal sharing of electrons such that one atom completely loses one or more electrons and the other atom gains one or more electrons, such as in the creation of an ionic bond between a metal atom (sodium) and a nonmetal
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