Question

1. when a substance changes from a solid to a liquid, it is undergoing which phase change?

a. condensation
b. freezing
c. melting
d. sublimation

1. which of the following is an example of a phase change from a gas to a liquid?

a. evaporation
b. deposition
c. condensation
d. sublimation

1. which of the following phase changes is exothermic, releasing heat to the surroundings?

a. melting
b. boiling
c. sublimation
d. condensation

1. what happens to the temperature of a substance during a phase change?

a. it increases
b. it decreases
c. it remains constant
d. it fluctuates

Explanation:

1. Melting is the phase - change from solid to liquid. Condensation is gas to liquid, freezing is liquid to solid, and sublimation is solid to gas.
2. Condensation is the phase - change from gas to liquid. Evaporation is liquid to gas, deposition is gas to solid, and sublimation is solid to gas.
3. Condensation is an exothermic phase - change. Melting, boiling, and sublimation are endothermic processes.
4. During a phase - change, the temperature of a substance remains constant as the heat energy is used for breaking or forming intermolecular forces instead of changing the kinetic energy of the molecules.

Answer:

1. c. Melting
2. c. Condensation
3. d. Condensation
4. c. It remains constant