The covalent alkaline earth metal halide ( $\mathrm{X}=\mathrm{Cl}, \mathrm{Br}, \mathrm{I}$ ) is:

JEE Main · 2019 · 08 Apr 2019 · Shift 2 · s-Block Elements

The covalent alkaline earth metal halide
(

X = Cl, Br, I

) is:

(A) $BeX_{2}$ ✓ Correct
(B) $CaX_{2}$
(C) $SrX_{2}$
(D) $MgX_{2}$

Answer: (A)

Solution

Fajan's rules say covalent character grows when the cation is small and strongly polarising and the anion is large and easily polarised. Among the alkaline earth metals

Be X^{2 +}

is by far the smallest cation, giving it the highest charge density and the strongest pull on the electron cloud of the halide ion. That makes

BeX X_{2}

the most covalent of the alkaline earth metal halides.

JEE Main · 2019 · 08 Apr 2019 · Shift 2 · Single correct option

Practise more: all JEE Main PYQs on s-Block Elements →

More JEE Main questions on s-Block Elements

The type of oxide formed by the element among $Li, Na, Be, Mg, B$ and Al that has the least atomic radius is :
JEE Main 2025View solution →
The $F^{-}$ 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.
JEE Main 2024View solution →
Number of metal ions characterized by flame test among the following is ____.
$Sr^{2 +}, Ba^{2 +}, Ca^{2 +}, Cu^{2 +}, Zn^{2 +}, Co^{2 +}, Fe^{2 +}$
JEE Main 2024View solution →
The setting time of Cement is increased by adding
JEE Main 2023View solution →
Ion having highest hydration enthalpy among the given alkaline earth metal ions is:-
JEE Main 2023View solution →
Structure of $BeCl_{2}$ in solid state, vapour phase and at very high temperature respectively are :-
JEE Main 2023View solution →