What are the ions? How is it formed?

Ions are atoms or molecules which have gained or lost one or more valence electrons, giving the ion a net positive or negative charge.

Cations are positively charged ions. They are formed when a metal loses its electrons. They lose one or more than one electron and do not lose any protons. Therefore they possess a net positive charge.

Some examples of cations are Calcium (Ca2+), Potassium (K+), hydrogen (H+).

Anions are negatively charged ions. They are formed when a nonmetal gains electrons. They gain one or more than one electron. Therefore they possess a net negative charge.

Some examples of anions are Chloride ions (Cl-), iodide(I-), Bromide ions (Br-).