Question

Why is warm water less dense?

Answer 1

The density of a liquid:

• A liquid's density is a measurement of how heavy it is in relation to the volume being measured.
• The heavier liquid is denser when two liquids are weighed in the same quantities or volumes.

Warm water:

• When water is heated, the gap between molecules widens.
• Hot water has more inter-molecular space than cold water and hence the volume increases.

Hence, warm water is less dense because the volume increases.