Question

Arrange the following as per instruction given in the brackets.
(a) Mg, Cl, Na, S, Si (decreasing order of atomic size)

Answer 1

• The atomic size decreases across the period.
• The elements Mg, Cl, Na, S, Si belong to the same period 3. Across the period, as the nuclear charge increases hence, the atomic size decreases.

Thus, the decreasing order of atomic size is,
Na > Mg > Si > S > Cl