Question

what do these two changes have in common? melting wax water evaporating from a lake select all that apply. both are only physical changes. both are chemical changes. both are caused by heating. both are caused by cooling.

Explanation:

1. Analyze "melting wax": Melting wax is a physical change (changes state from solid to liquid, no new substance formed) and is caused by heating (heat energy is added to melt the wax).
2. Analyze "water evaporating from a lake": Evaporating water is a physical change (liquid to gas, no new substance) and is caused by heating (sun's heat or ambient heat causes evaporation).
3. Evaluate options:

• "Both are only physical changes": Correct, as both changes don't form new substances, just change state.
• "Both are chemical changes": Incorrect, no chemical reactions occur (no new substances).
• "Both are caused by heating": Correct, melting wax needs heat, evaporation of water (from a lake, typically) is driven by heat (e.g., solar heat).
• "Both are caused by cooling": Incorrect, cooling would solidify wax or condense water, not melt or evaporate.

Answer:

A. Both are only physical changes, C. Both are caused by heating