Question

what do these two changes have in common?
a puddle freezing into ice on a cold night
dust settling out of the air
select all that apply.
both are only physical changes. both are chemical changes.
both are caused by heating. both are caused by cooling.

Explanation:

• Physical vs Chemical Changes: Physical changes involve a change in state or appearance without altering the substance's chemical composition. Chemical changes result in the formation of new substances. A puddle freezing into ice is a physical change (change of state from liquid to solid), and dust settling out of the air is also a physical change (separation of particles).
• Cause Analysis: Freezing (puddle to ice) is caused by cooling (removal of heat). Dust settling is a physical separation process not caused by heating.

Answer:

A. Both are only physical changes.