Alkali metals .........

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The alkali metals and their salts impart characteristic colour to reducing flame.
Reason $R$: Alkali metals can be detected using flame tests.
In the light of the above statements,choose the most appropriate answer from the options given below.

The incorrect statement regarding the above reactions is:
$Al_{(metal)} \xrightarrow[HCl]{(aq.)} 'X' + \text{Gas } 'P'$
$Al_{(metal)} \xrightarrow[NaOH (aq.)]{+ H_2O} 'Y' + \text{Gas } 'Q'$

Statement $I$: An alloy of lithium and magnesium is used to make aircraft plates.
Statement $II$: The magnesium ions are important for cell-membrane integrity.
In the light of the above statements,choose the correct answer from the options given below.

Sodium chloride gives a golden yellow flame in a Bunsen burner. What can be inferred from this?

All the $s$-block elements of the periodic table are placed in the groups...