Question

Convection works because __________.

A. materials are denser when they are hot
B. heat travels from cold to hot regions on Earth
C. materials are denser when they are cold
D. cold materials are liquids

Answer 1

Convection is the transfer of thermal energy by the movement of a liquid or gas. Convection works when a liquid or gas is unevenly heated. Hot liquids (and gases) are less dense and rise, causing. The warmer section of the material will rise while the cooler part sinks.