Use the drop-down menus to complete the statements. are pure substances that cannot be broken down into a simpler form. are units of two or more atoms. are the smallest possible particles of an element. are pure substances made of two or more atoms of different elements.

Please see below

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 moleculeH2O (water),C6H12O6 (glucose)