Atoms, Elements and Compounds
All substances are made up of atoms, an atom is the smallest part of an element that is possible. An atom of an element is represented by either one or two letters, for example, the chemical symbol of an atom of magnesium is Mg and the symbol of an atom of oxygen is O.
An atom consists of a nucleus (containing neutrons and protons), electrons and shells.
An element cannot be broken down into any other substance, There are more than 100 different elements and each contains its own atoms. Everything in the universe is made up of one or more different elements. All of the known elements are listed on the periodic table.
A compound is a mixture of two or more different elements. The different elements are chemically bonded together in the formation of a compound. There are different types of bonds which cab hold a compound together, these are, ionic bond or a covalent bond