The statement that correctly describes compounds is:
"Compounds can be broken down into simpler substances by chemical means."
To elaborate:
- Compounds are made up of two or more different elements that are chemically bonded together, which means they can be broken down into those elements or simpler compounds through chemical reactions, but not by physical means.
- Each compound is composed of molecules that can contain different types of atoms, so the statement "Each compound is composed of one type of molecule" is incorrect.
- The statement "Each compound is composed of one type of atom" is incorrect because compounds are, by definition, made up of different types of atoms.
Thus, the correct characterization of compounds is related to their ability to be broken down through chemical processes.