MATTER There are three basic states of matter: solid, liquid and gas. Everything on earth is made up of microscopic particles (molecules or atoms) and the speed and density of these particles determine which state of matter an object is. SOLID A solid is anything that holds a particular size and shape. An apple, a block of wood, and a penny are all solids. The particles in a solid are tightly packed and do not move much. LIQUID A liquid is anything that has size or volume, but does not have a shape. Liquids take on the shape of their container such as a cup, bottle or receptacle. Liquid particles are not as close together as particles in a solid and move around much more freely. GAS Gases are hard to identify because they have no color or shape. The particles in a gas move freely at high speeds.