4. What type of substance would be best for use in a heating system?

A liquid with a high specific heat

A liquid with a low specific heat

A gas with a low specific heat

An explanation of why the answer is right.

The best answer is a liquid with low specific heat. For every heating medium used in a heating system, it is important to have a substance with a low specific heat, so that it will easily reach the desired heating temperature. This saves on cost because you will need less energy to increase the temperature of your medium. A liquid is also better than a gas because liquids are able to give off more energy (latent and sensible heat) than gases.