Question

question 13
1 pts
thermal contraction and expansion is when a substance expands when
and contracts when .

Explanation:

Thermal expansion and contraction are physical phenomena related to temperature changes. Substances generally expand as temperature increases (due to increased molecular motion and spacing) and contract as temperature decreases (molecular motion slows, spacing reduces). This is a concept in Physics (a subfield of Natural Science) dealing with thermal properties of matter.

Answer:

The first blank: heated (or "temperature increases")
The second blank: cooled (or "temperature decreases")