In most cases, what happens to a liquid when it cools?

1. its density increases

2. its density decreases

3. its mass increases

4. its mass decreases

5. its volume increases

6. its volume decreases

When liquid cools, both its density and volume increases. Therefore the answer to your question are #s 1 and 5. This is due to the fact that molecules which are compacted or pressed against each other form a solid, and when they start to cool-down the molecules start to break free from each other increasing the density of a liquid and the space that it occupies.