Select the elementary substance.
A: graphite (C)
B: hydrazine (N2H4)
C: pyrite (FeS2)
Look at the chemical formula for each substance, and count the number of symbols in the formula. Then, decide if the substance is an elementary substance. The chemical formula for graphite contains one symbol: C for carbon. So, graphite is made of one chemical element. Substances that are made of one chemical element are elementary substances. So, graphite is an elementary substance. The chemical formula for hydrazine contains two symbols: N for nitrogen and H for hydrogen. So, hydrazine is made of two chemical elements bonded together. Substances that are made of two or more chemical elements bonded together are compounds. So, hydrazine is a compound, not an elementary substance. The chemical formula for pyrite contains two symbols: Fe for iron and S for sulfur. So, pyrite is made of two chemical elements bonded together. Substances that are made of two or more chemical elements bonded together are compounds. So, pyrite is a compound, not an elementary substance.