Question

Which of the following statement (s) is/are true for $IA$ elements?

• A. Na is regarded as a typical representative element.
• B. Basic character of their oxides increases down the group.
• C. Among alkali metal ions degree of hydration is the highest in Li.
• D. In general electron afnity values decrease from top to bottom in the group.

Answer 1

Answer: (A), (B), (C), (D)

(a) $s$ and $p$ - block elements are collectively called as representative elements.
(b) As metallic character, i.e., electropositive character increases, the basic nature of metal oxides increases.
(c) Hydration $\alpha \frac{\text{ Charge on cation }}{\text{ Size of cation }}$
(d) As the size of atom increases, the distance between nucleus and extra electron increases and thus attraction between them decreases. Hence, generally electron affinity decreases (exception third period elements).