Question

for each example of a phase change, identify whether heat is absorbed from the surroundings or released into the surroundings.
a popsicle melts on a hot day.
rubbing alcohol evaporates from the surface of the skin.
lava solidifies when it erupts from a volcano.

Explanation:

Step1: Analyze Popsicle Melting

Melting is a phase change from solid to liquid. This process requires heat energy, so the popsicle absorbs heat from the surroundings (the hot day environment) to melt.

Step2: Analyze Alcohol Evaporation

Evaporation is a phase change from liquid to gas. This process also requires heat energy, so the rubbing alcohol absorbs heat from the skin (the surroundings relative to the alcohol) to evaporate.

Step3: Analyze Lava Solidification

Solidification is a phase change from liquid to solid. This process releases heat energy because the liquid loses energy to become a solid, so the lava releases heat into the surroundings.

Answer:

• A popsicle melts on a hot day: Heat is absorbed from the surroundings.
• Rubbing alcohol evaporates from the surface of the skin: Heat is absorbed from the surroundings.
• Lava solidifies when it erupts from a volcano: Heat is released into the surroundings.