Answer:
This makes them move faster and further apart and the substance expands. This makes the object's volume increase which changes causes the density to decrease.
When a substance is cooled, the particles lose energy. This makes them move slower and closer together and the substance contracts. This makes the object's volume decrease which changes causes the density to increase.
Explanation:
When an object is heating up its molecules will move faster and expand the object, this means the volume is increasing. Density is equal to mass over volume meaning if the volume is increasing the density will decrease. The opposite is true for when the substance is cooled. Molecules will move slower and the object will contract. The volume will decrease and the density will increase.
