Question

Which are true statements about s - block elements? ( more than one option is correct )
A. Metals are obtained by electrolysis of fused electrolytes.
B. Oxides are Basic except $BeO$ .
C. +1 valency by alkali metals and +2 valency alkaline earth metals is shown.
D. Carbonates are thermally stable.

Answer 1

The s block elements are elements present in the group 1 and group 2 of modern periodic table. The s block elements have either 1 or 2 valence electrons in atoms.

Complete Step By Step Solution:

Let’s first look at what is s - block elements.
s- Block elements: The elements present in group 1 and group 2 of modern periodic table are called s block elements. The outermost subshell of s block elements are either ${s^1}$ or ${s^2}$ . There are a total 14 elements in the block.

Let’s look at the all properties one by one:
1. Metals are obtained by electrolysis of fused electrolytes which is true. So the 1st statement is true.
2. Metal oxides are basic in nature because they furnish into $O{H^ - }$ ions when reacted with water. And s block elements are metals so their oxides are basic in nature. But in the case of $BeO$ it does not show basic nature because it does not react with water like bases do so $BeO$it does not show basicity. So the 2nd statement is true.
3. Electronic configurations of alkali and alkaline earth metals are $n{s^1}$ and $n{s^2}$ so their valencies are +1 and +2 respectively. So the third statement is also true.
4. Carbonates of all alkali metals are not thermally stable. Only sodium carbonate is thermally stable, others like $Ca$ and $Li$ carbonates decompose on heating. So the 4th statement is not correct.

**So the correct options are 1st , 2nd and 3rd .

Note: **
$BeO$ is amphoteric in nature, that is it shows properties of acids as well as bases. It reacts with acids as well as bases so it is amphoteric and not basic.