Which element is a brittle solid with low conductivity at STP?

(1) sulfur (3) argon

(2) sodium (4) aluminum

Sulfur is the element that is a brittle solid with low conductivity at STP.

Answer: option (1) sulfur.

Explanation:

1) Brittleness and low conductivity are known properties of solid non-metals.

2) On the contrary, solid metals are known for their ductibility, malleability, and high electrical and thermal conductivity.

3) Sulfur is a non-metal, solid at STP (standard temperature and pressure), so you can expect that it is brittle and a poor conductor.

4) Sodium is a metal, hence it is ductile, malleable and good conductor of electricity and heat.

5) Argon is a non-metal gas at STP, ergo it is not solid.

6) Aluminun is a metal, so it is also ductile, malleable and good conductor.