Section 1: Composition of Matter
Matter is anything that has mass and takes up space. Matter can be divided into mixtures and pure substances. A substance is a type of matter with a fixed composition that cannot be separated by physical means. These pure substances are either elements or compounds. An element is a substance made up of atoms with the same identity such as gold, helium, and aluminum. A compound has atoms of two or more elements combined such as water (H20) and carbon dioxide (CO2).
A mixture is a material that is made up of two or more substances that can be separated by physical means. Mixtures are characterized in two ways. A heterogeneous mixture is a mixture in which different materials are easily identifiable and can be separated from each other. A fruit salad is comprised of several different types of fruit. A homogeneous mixture is one in which two or more substances are uniformly spread out so that you cannot see one separate from another such as vinegar and saltwater.