Which one of the following metallic hydroxides does not dissolve in sodium hydroxide solution?

Assertion : $s-$Block elements do not occur free in nature.
Reason : $s-$Block elements are highly electropositive in nature.

$A$ white solid '$A$' on heating produces a gas that turns lime water milky,and the remaining solid residue is yellow when hot but turns white on cooling. The solid '$A$' is:

Write a note on $s$-block elements of the periodic table.

Soda lime is made from

Identify the correct statements from the following:
$I$. $LiF$ is less soluble in water than $NaF$
$II$. Both $LiCl$ and $MgCl_2$ are insoluble in ethanol
$III$. Both $Li$ and $Mg$ form nitrides
$IV$. $Na_2CO_3$ gives $CO_2$ on heating