Question

what do these two changes have in common?
a puddle freezing into ice on a cold night
water evaporating from a puddle
select all that apply.
both are only physical changes.
both are chemical changes.
both are caused by heating.
both are caused by cooling.
submit

Explanation:

1. Analyze the first change (puddle freezing to ice): Freezing is a phase change from liquid to solid (water to ice). No new substance is formed, so it's a physical change. It occurs due to cooling (cold night).
2. Analyze the second change (water evaporating from a puddle): Evaporation is a phase change from liquid to gas (water to water vapor). No new substance is formed, so it's a physical change. It occurs due to heating (energy from the environment, like sunlight, provides heat for evaporation).
3. Evaluate the options:

• "Both are only physical changes": Correct, as both freezing and evaporation are phase changes (physical changes, no new substances).
• "Both are chemical changes": Incorrect, as no chemical reactions (no new substances) occur in either change.
• "Both are caused by heating": Incorrect, freezing is caused by cooling, evaporation by heating.
• "Both are caused by cooling": Incorrect, evaporation is caused by heating, freezing by cooling.

Answer:

A. Both are only physical changes.