Which statement is true of pure substances?

Question

Responses

They can only contain one type of atom.
They can only contain one type of atom.

They may contain one type of atom or one type of molecule.
They may contain one type of atom or one type of molecule.

They can contain different types of atoms and molecules.
They can contain different types of atoms and molecules.

They can only contain one type of molecule.

Answer 1

The correct statement about pure substances is:

They may contain one type of atom or one type of molecule.

Pure substances can be elements (which consist of only one type of atom) or compounds (which consist of one type of molecule made up of two or more types of atoms chemically bonded together).