What is an ion? Explain the types of ion with examples.

An ion is a positively or negatively charged atom or groups of atoms. There are two types of ions: An atom loses one or more electrons from its valence shell. It becomes positively charged. These positively charged atoms are called cations. For example, Sodium (Na) atomic number is 11. So, there is one electron in the valence shell. To stabilize the atom, sodium loses one electron and is a deficit of the negative charge. This will give rise to sodium ion. Na+ When an atom gains one or more electrons into its valence shell, it becomes negatively charged. These negatively charged atoms are called anions. For example, the atomic number of Chlorine (Cl) is 17. So, it has seven valence electron and requires one electron to become stable. Thus, chlorine gains one electron and becomes negatively charge. This is called a chloride ion (Cl-) Since there is a loss of electrons in a cation, there is a possibility f losing a shall. Hence the size of a cation is smalled. Since there is a gain of electrons for an anion, there is more number of electrons, causing the shells to repel. This si the reason why an anion is always bigger than its original atom size. read less