Question

thermal contraction refers to what?
as heat decreases, mass decreases.
as heat decreases, volume decreases.
as heat decreases, weight decreases.

Explanation:

Thermal contraction is a physical phenomenon. Mass is an inherent property of matter and does not change with heat (in non - nuclear, non - relativistic situations). Weight is related to mass and gravitational acceleration, and also does not change due to heat in a local gravitational field. Volume, on the other hand, changes with temperature. When heat (temperature) decreases, for most substances, the volume decreases, which is the essence of thermal contraction.

Answer:

As heat decreases, volume decreases.