Question

Which of the following solids is not an electrical conductor?

• A. ${\mathrm{I}}_2$
• B. $\mathrm{Mg}$
• C. ${\mathrm{H}}_2$
• D. Both A and C

Answer 1

The correct option is D

Both A and C

The explanation for the correct option:

(D) Both A and C

• In Iodine gas$\left({\mathrm{I}}_2\right)$, the covalent bond is very strong and cannot be excited sufficiently to transfer electrical energy.
• Magnesium$\left(\mathrm{Mg}\right)$ conducts electricity because it is a metal.
• In Hydrogen gas$\left({\mathrm{H}}_2\right)$, the covalent bond is very strong and cannot be excited sufficiently to transfer electrical energy.

Hence, Option (D) Both A and C is the correct answer.

The explanation for the incorrect options:

(A) ${\mathbf{I}}_{\mathbf{2}}$

• Each molecule of Iodine is made up of two Iodine atoms joined by a covalent bond so Iodine gas does not conduct electricity.
• This covalent bond in Iodine gas is very strong and cannot be excited sufficiently to transfer electrical energy.
• Only option (A) is not the correct answer.

(B) $\mathbf{Mg}$

• Magnesium is a metal so it can conduct electricity.
• It is bonded with a metallic bond and a sea of delocalized electrons surrounds the Magnesium ions.
• These electrons can conduct electricity as current is formed by the motion of existing electrons.

(C) ${\mathbf{H}}_{\mathbf{2}}$

• Each molecule of Hydrogen is made up of two hydrogen atoms joined by a covalent bond so Hydrogen gas does not conduct electricity.
• This covalent bond in Hydrogen gas is very strong and cannot be excited sufficiently to transfer electrical energy.
• Only option (C) is not the correct answer.

Therefore, Option (D) Both A and C are correct. answer.