Question

The bond angle is minimum in
A. \[H{_{2}}Te\]
B. \[H{_{2}}Se\]
C. \[H{_{2}}O\]
D. \[H{_{2}}S\]

Answer 1

Hint: The bond angle is the angle made by two bonds originating from a single atom.
It contributes to the shape of a molecule.

Complete step by step solution:Here in this question, we have to find the minimum bond angle found in which molecule.
The given options have common element hydrogen which is bonded to O, S, Se, and Te respectively.
These elements belong to the oxygen family.
We know that electronegativity and size impact bond angles and molecular geometry.
The electronegativity of an atom is the inclination of an atom to attract electrons to itself in a chemical bond.
As the central atom expands in size, the bond lengths also rise and the other atoms are distant from each other in space.
According to the VSEPR theory, this will lessen steric relations between the atoms.
Due to the lone pair on these molecules being additionally repulsive than bonded groups, the reduction in steric interactions between bonded groups gives a decrease in bond angles.
When an atom is additionally electronegative, it will drag the electrons toward itself and away from the central atom.
This will lessen the electron pair repulsion between bonded electron pairs on the central atom.
Down the group, electronegativity decreases.
A decline in electron pair repulsion on the central atom reduces bond angles between the groups.
So, down the group bond angle decreases.
So, the bond angle is minimum in \[H{_{2}}Te\].

So, option A is correct.

Note: Electronegativity reduces as we go down the group as we go down the group, the atomic size grows, and the effective nuclear charge reduces.
Accordingly, the inclination to draw shared pairs of electrons diminishes, lowering electronegativity.