A+ b + c → d + e
describe the mass of the reactants and products given the balanced chemical reaction.
a. the mass of the products is 2/3 that of the reactants.
b. the mass of the reactants equals the mass of the products.
c. the mass of the reactants is less than the mass of the products.
d. the mass of the reactants is greater than the mass of the products.

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.

i think the answer is terrae but not 100 percent sure. ▓▬▬ §