Matter Anything that has mass + volume divisions of matter pure substances and mixtures Pure Substance A sample of matter, either a single element or a single compound, that has definite chemical and physical properties EX: O, H, CL, ( elements ) Compounds: H20, NaCL definite properties: always the same Heterogenous mixtures are... mixtures that are not uniform throughout Oil and water - creating a distinct boundary Homogenous mixture example a mixture in which the composition is uniform throughout salt water Is blood homogeneous or heterogeneous? blood under microscope is heterogenous regular blood is homogenous Mass A measure / quantity of the amount of matter in an object Volume