Question

Which of the following solids is not an electrical conductor?

(A) $Mg\left(s\right)$
(B) $TiO\left(s\right)$
(C) $I_2\left(s\right)$
(D) $H_{2}O\left(s\right)$

• A. $\left(B\right)$ only
• B. $\left(B\right),\left(C\right)$ and $\left(D\right)$
• C. $\left(A\right)$ only
• D. $\left(C\right)$ and $\left(D\right)$

Answer 1

The correct option is D $\left(C\right)$ and $\left(D\right)$

$\text{Analyzing the solids}$

(A) $Mg\left(s\right)$

$Mg\left(s\right)$, which is metal and has electrical conductivity properties because it has free and mobile electrons (valence shell) which are present evenly throughout the solid.

(B) $TiO\left(s\right)$

$TiO\left(s\right)$ which behaves like a metal can also conduct electricity because in the d-orbital electrons are partially filled, which led to electrical conductivity in the solid.

(C) $I_2\left(s\right)$

The $I_2\left(s\right)$ molecules are attracted with other similar molecules via London forces which led to formation of non-polar molecular solids. These solids do not conduct electricity.

(D) $H_{2}O\left(s\right)$

$H_{2}O\left(s\right)$ i.e., ice . It is a hydrogen-bonded molecular crystalline solid. Hence, this also does not conduct electricity.
Molecular solids do not conduct electricity.
Hence, $I_2\left(s\right)$ and $H_{2}O\left(s\right)$ do not conduct electricity.

Thus, option $\left(C\right)$ is the correct answer.