Question

How ions are formed ?

Answer 1

An ion is a chemical species with a net electric charge formed when a neutral atom or a group of atoms accepts or donates one or more electrons. Ions are of two types - cations and anions. The cations are formed when a neutral atom loses one or more electrons. It has less electrons than the neutral atom and is therefore positively charged. Example sodium atom (Na) on losing an electron forms sodium cation, denoted by Na+, calcium atom on losing two electrons forms calcium ion, denoted by Ca2+.
Similarly, anions are formed when neutral atom gains one or more electrons. It has more electrons than the neutral atom and is therefore negatively charged. chlorine forms a negative chloride ion, Cl- (anion) by accepting one electron.