What are ions? Under what conditions are they produced?

ANSWER:

IONS:

“Those species which carry either positive or negative charge are called ions.”

Examples: K⁺, Mg²⁺, Al³⁺, Cl^–, O^2–, CO₃^2– etc.

Conditions for the Formation of Ions:

1) Positive ions or cations are produced when an atom loses one or more electrons. A sufficient amount of energy is to be provided to a neutral atom to ionize it. e.g.,

M ⟶ M⁺ + e^–     ∆H = Positive

2) Negative ions or anions are formed when an atom gains one or more electrons. Energy is usually released when an electron is added to an isolated neutral atom. e.g.,

B + e^–  ⟶  B^–      ∆H = Negative

(Ref. An Insight Into Objective Chemsitry-11, Ch-01, Q. No. 09)