Which describes a compound?
a substance than cannot be broken down in simpler parts
a chemical combination of two or more elements
a material that is made of only one type of atom
a substance like phosphorus, hydrogen, nitrogen, or sulfur
a substance than cannot be broken down in simpler parts
a chemical combination of two or more elements
a material that is made of only one type of atom
a substance like phosphorus, hydrogen, nitrogen, or sulfur