Question

Which of the following solids cannot conduct electricity?
$1.\text{Graphite}2.Cs3.\text{Diamond}$

• A. $1\text{and}2$
• B. $1\text{and}3$
• C. Only $2$
• D. Only $3$

Answer 1

The correct option is D Only $3$

$\text{Cs}$ is a metal. So it is a good conductor of electricity.
We know covalent solids can't conduct electricity.
$\text{Diamond}$ is insulator since it is a covalent solid.
Even though graphite is a covalent solid, it can conduct electricity due to the presence of delocalised electrons in it.