Question

Choose the correct statements.

i. Ionisation energy of sodium is less than that of magnesium.

ii. Atomic size of sodium is less than that of magnesium.

iii. Metallic character of sodium is greater than that of magnesium.

iv. Reactivity of sodium is less than the reactivity of magnesium.

[1 mark]

• A. (i) and (ii)
• B. (i) and (iii)
• C. (ii) and (iv)
• D. (ii) and (iii)

Answer 1

The correct option is B (i) and (iii)

The location of sodium and magnesium in the periodic table is as follows:

	Group 1	Group 2
Period 3	Na	Mg

• As we go from left to right across a period, the ionisation energy increases. Hence, statement (i), i.e., ionisation energy of sodium is less than ionisation energy of magnesium is correct.
• As we go from left to right across a period, the atomic size decreases. Hence, statement (ii), i.e., atomic size of sodium is less than atomic size of magnesium is incorrect.
• As we go from left to right across a period, the metallic character decreases. Hence, statement (iii), i.e., metallic character of sodium is greater than metallic character of magnesium is correct.
• As we go from left to right across a period, the reactivity decreases. Hence, statement (iv), i.e., reactivity of sodium is less than the reactivity of magnesium is incorrect.