Question

which statement best describes the change to an ice cube as it melts?
the change is physical because the substance remains the same
the change is physical because the mass remains the same.
the change is chemical because water has a different ph than ice.
the change is chemical because ice has a lower density than water.

Explanation:

A physical change is a change in which the substance remains the same. When ice melts, it changes from solid to liquid, but it is still water (\(H_2O\)). In a chemical change, a new substance is formed. Mass remaining the same is not the best criterion for a physical change (though it is a law of conservation of mass in general). pH is related to chemical properties (acidity - basicity) and density is a physical property but the key is that the substance remains \(H_2O\).

Answer:

The change is physical because the substance remains the same.