Question

As air becomes more dense, _____. (Select all that apply)

Answer 1

The answers that apply are;

1. gas molecules are closer together
2. air weighs more
3. air is hotter

When air is compressed, it means the same volume of space is occupied by more air molecules. This, therefore, means that the molecules are hitting each other with a higher frequency hence become hotter with more compression. It weighs more because there are more molecules in the same volume of space.