One thing that happens is that the molecules in the matter lose energy and momentum and slow down, therefore the matter becomes more compact.
The density of the substance becomes higher because of the particles slow down and move closer together when the substance cools.
When energy is removed from matter, the matter typically cools down and its particles slow down in movement. This can lead to changes in the physical state of the matter, such as condensation or solidification. However, the matter itself remains the same in terms of its chemical composition.
Use particle theory of matter to describe what happens to the density of a substance when it cools down
guess
It expands and cools
As air cools, the space it occupies becomes less. This results in an increase in density.
as air cools, the space it occupies becomes less. this result in an increas density
It forms igneous rock.
it cools
It becomes a Igneous rock.
the density increases
it cools down