Answer: Please see below
Step-by-step explanation:
Are pure substances that cannot be broken down into a simpler form---- Element
are units of two or more atoms---- Molecule
are the smallest possible particles of an element---- an Atom
are pure substances made of two or more atoms of different elements---- Compound
An atom is the smallest unit of matter that consists of protons, neutrons and electrons. Eg the element, helium, contains atoms with two protons in the nucleus.
Eg of element, we have carbon, hydrogen, helium
Eg of a compound--- Ammonia
Eg of a molecule-----H2O (water),C6H12O6 (glucose)