How are nuclear fission and nuclear fusion similar? A. Both processes combine smaller nuclei into larger nuclei.
B. Both processes convert mass into energy.
C. Both processes are used to produce electrical power.
D. Both processes occur in stars.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

a is the correct answer