Question

1. a change in matter in which the density of the matter stays the same

Explanation:

The question is about a type of change in matter where density remains the same. In natural science (specifically chemistry or physics), a physical change is a change in matter where the substance's chemical identity doesn't change, and properties like density (if the substance remains the same) can stay constant. For example, changing the shape or state of a substance (like melting ice to water, though density of water and ice differ, but other physical changes like cutting a piece of metal) where the chemical composition isn't altered, and if the substance is the same, density remains. So the term for this is a physical change.

Answer:

physical change