Question

what do these two changes have in common? breaking a piece of glass dry ice sublimating and becoming a gas select all that apply. both are only physical changes. both are chemical changes. both are caused by heating. both are caused by cooling.

Explanation:

Step1: Define physical and chemical changes

A physical change alters a substance's form but not its chemical composition. A chemical change transforms substances into new ones.
Breaking glass changes its form (physical). Dry - ice sublimation (solid to gas) is a physical state change.

Step2: Analyze heating/cooling causes

Breaking glass isn't due to heating/cooling. Dry - ice sublimation is due to heat (absorbs heat from surroundings).

Answer:

Both are only physical changes.