When a pure solid substance was heated, a student obtained another solid and a gas, each of which was a pure substance. From this information which of the following statements is ALWAYS a correct conclusion?
a. both products are elements
b. both products are compounds
c. the original solid is not an element
d. the original solid is a compound and the gas is an element
e. the original solid is an element and the gas is a compound
a. both products are elements
b. both products are compounds
c. the original solid is not an element
d. the original solid is a compound and the gas is an element
e. the original solid is an element and the gas is a compound