Question

(a) What is an ion? Explain with examples.
(b) What is the nature of charge on (i) a cation, and (ii) an anion?
(c) Name the cation and anion present in MgCl₂. Also write their symbols.

Answer 1

(a) An electrically-charged atom (or group of atoms) is called an ion. it is formed by the loss or gain of an electron by an atom.
Ions are of two types: cations and anions.
For example: A sodium ion (Na⁺) is formed when a sodium atom loses one electron. A sodium ion is a cation.
A chloride ion (Cl^-) is formed when a chlorine atom gains one electron. A chloride ion is an anion.

(b) (i) The charge on a cation is positive.
(ii) The charge on an anion is negative.

(c) The cation present in MgCl₂ is a magnesium ion that is represented as Mg²⁺ and the anion present is a chloride ion that is represented by Cl^-.