Question

Match the statements of Column A (Description of atoms forming the molecules) with those of Column B (Forces of attraction among the molecules)

Column 1	Column 2
A has 7protons and B has 1 proton.	Interionic attraction
Both the atoms have identical electronic configurations.	Dipole-dipole interaction
A has 20 protons and B has 8 protons.	H— bonding
A has 1 proton and B has 16 protons.	Van der Waals’ forces of attraction

Answer 1

Explanation of correct matching

Atomic number - The number of protons of an atom in its ground state.

A-III

• A is Nitrogen ($\mathrm{N};\mathrm{Z}=7$) and B is Hydrogen ($\mathrm{H};\mathrm{Z}=1$). They will form Ammonia (${\mathrm{NH}}_3$).
• Ammonia has intermolecular H-bonding.
• ${\mathrm{H}}_3\mathrm{N}\cdots \cdots \mathrm{H}-{\mathrm{NH}}_2$

B-IV

• Both the atoms have identical electronic configurations means they will form a non-polar homo-diatomic molecule.
• These kinds of molecules usually have a London force of attraction which is one of Van der Waal's forces of attraction.

C-I

• A is Calcium ($\mathrm{Ca};\mathrm{Z}=20$) and B is Oxygen ($\mathrm{O};\mathrm{Z}=8$).
• The compound they form is Calcium oxide ($\mathrm{CaO}$). Calcium oxide is an ionic compound.
• The cation ${\mathrm{Ca}}^{2+}$ and anion ${\mathrm{O}}^{2-}$ will have an interionic attraction between them.

D-II

• A is Hydrogen ($\mathrm{H};\mathrm{Z}=1$) and Sulphur ($\mathrm{S};\mathrm{Z}=16$).
• The compound they will form is Hydrogen sulphide (${\mathrm{H}}_2\mathrm{S}$).
• In ${\mathrm{H}}_2\mathrm{S}$ there is a difference in electronegativity between $\mathrm{H}$ and $\mathrm{S}$ and because of that the molecule has dipolar nature.
• Thus, ${\mathrm{H}}_2\mathrm{S}$ molecules have dipole-dipole interaction between themselves.

Thus, the correct sequence of matching is A-III; B-IV; C-I; D-II.