Question

solid water floats on liquid water. why does this happen? ice is less dense than water vapor ice is less dense than liquid water

Explanation:

The principle of buoyancy states that an object floats when it is less dense than the fluid it is placed in. In this case, solid water (ice) floats on liquid water because ice has a lower density than liquid water. Water vapor is a gas, and comparing ice (solid) density to water vapor (gas) density is not relevant to why ice floats on liquid water.

Answer:

Ice is less dense than liquid water.