Which is not proof that a chemical change has occurred?
a. the color changes
b. a precipitate forms
c. the substance melts
d. bubbles are produced

the substance melts

Choice C

Explanation:

A chemical change refers a process by which one substance changes into a new substance with different properties with the formation of one or more new substances.

Color change, formation of a precipitate and production of bubbles all indicate the occurrence of a chemical change. On the other hand, melting is purely a physical change since no new substance is formed and the process can easily be reversed through freezing.

c

explanation:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs