Composition of Matter
All matter is composed of atoms. The number of electrons, protons and electrons, determine the properties of those atoms. Matter is made up of elements. Elements are atoms with specific properties. The main property that defines each element are the number of electrons, proton and neutrons. An example would be that of hydrogen and helium. Both of these are elements. They both have electrons, protons and neutrons but the numbers of each are different. That difference alone allow for different chemical and physical properties. An element is defined as matter that is made up of the same kind of atoms. All sodium atoms have the same physical and chemical properties. All nickel elements have the same chemical and physical properties, although those properties that define each of the preceding elements are exclusive to those elements alone. There are 111 recognized elements and they are categorized according to their properties on the Periodic Table.
A compound is composed of two or more elements of different kinds that are combined. The elements that make up a compound are always composed with the same elements in the same ratios every time. Glucose is always composed of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms. The properties of a compound are different than the elements from which it is made.
Back Mixtures & Solutions Phy. Sci. Main Page Describing Matter