This is the last question i need someone answer it fast rocks, like this schist, are composed of minerals. minerals have an exact crystal structure. rocks, minerals, and crystals are all made of a) atoms. b) compounds. c) mixtures. d) molecules.

The correct answer is (a) atoms. Atoms are the smallest constituent unit of ordinary matter that has the properties of a chemical element. Combined, atoms form chemical compounds such as molecules. Minerals are specific chemical compounds, usually of crystalline form, that form rocks (solid aggregate of one or more minerals or mineraloids).

Mg is used to measure mass