1. Convection
Investigation 5 Part 2

2. Convection
As heat is absorbed by fluids, the molecules move faster and bang into each other with greater frequency and force. This drives the molecules farther apart, making it less dense.

3. Convection Convection-
When a mass of fluid, either liquid or gas, is warmer or colder than the surrounding fluid, the mass will rise or sink in the surrounding fluid.
This motion of masses or streams of fluid, due to difference in density resulting from temperature, is convection.
Convection is the third way heat moves from one place to another.
Convection only happens in fluids, where molecules are free to flow.