Matter can be classified into three categories:elements compound, and mixtures.A substance made of just one type of atom is an elements.Presently,there are 109 known elements.Of these,90 elements are found in nature such as iron,carbon,oxygen,and nitrogen.Others are made in nuclear physics laboratories.Copper or a copper wire is made of only copper atoms. Carbon is made of only carbon atoms.Copper,carbon,lead,iron,and gold are examples of elements.You probably recognize some of the elements listed.Copper is used for electrical wires and cables.Aluminium is used in some cookware or utensils.Gold and silver are used in the jewelry industry and dentistry.Substances containing calcium and phosphorus are essential for strong bones and teeth.Hydrogen and oxygen make up water