Question

You are able to observe the release of energy in reactions in the form of what?

Heat, light or sound

Heat only

Light only

Sound only

Question 19 (Multiple Choice Worth 2 points)

What is the change that occurs when a substance changes from a solid to a liquid?

Melting

Boiling

Evaporation

Condensation

Question 20 (Multiple Choice Worth 2 points)

A reaction that gives off heat energy is known as

exothermic.

endothermic.

dynothermic.

energy producing.

Answer 1

@Travrob

Answer 2

Heat, sound, and light production are all signs of energy release.So A for the first one.
Melting is going from solid to liquid. Boiling is going right before a liquid turns into gas. Evaporation is liquid to gas. condensation is gas to liquid. So A.
exothermic gives off heat(becomes hot), endothermic takes in heat(becomes cold), so answer is A.