JEE Main · 2023 · 06 Apr 2023 · Shift 2 · s-Block Elements

The type of oxide formed by the element among $\mathrm{Li},\mathrm{Na},\mathrm{Be},\mathrm{Mg},\mathrm{B}$ and Al that has the least atomic radius is :

The ${\mathrm{F}}^{-}$ions make the enamel on teeth much harder by converting hydroxyapatite (the enamel on the surface of teeth) into much harder fluoroapatite having the formula.

Number of metal ions characterized by flame test among the following is ____.
${\mathrm{Sr}}^{2+},{\mathrm{Ba}}^{2+},{\mathrm{Ca}}^{2+},{\mathrm{Cu}}^{2+},{\mathrm{Zn}}^{2+},{\mathrm{Co}}^{2+},{\mathrm{Fe}}^{2+}$

The setting time of Cement is increased by adding

Structure of ${\mathrm{BeCl}}_2$ in solid state, vapour phase and at very high temperature respectively are :-

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R
Assertion A :- Sodium is about 30 times as abundant as potassium in the oceans.
Reason R :- Potassium is bigger in size than sodium.
In the light of above statements, choose the …