This document discusses the three states of matter and their properties. It defines matter as anything that has mass and occupies space, and defines the three states as solid, liquid, and gas. Solids have a definite shape and size, liquids take the shape of their container, and gases fill their container uniformly. Non-matter is also discussed as not having mass or occupying space, with examples given of gravity, light, sound, heat and electricity. Density is defined as the mass per unit volume, and examples are given to illustrate density comparisons between objects and liquids.