The periodic table lists about 120 known elements, naturally discovered or artificially prepared. Each of these elements falls under one of the 18 groups of the table. However, these elements may even be broadly divided into categories like metals, nonmetals and metalloids.

A metal is a substance that exhibits a shiny appearance when freshly processed, polished, or shattered, conducts electricity and heat rather well and usually has a very high oxidation tendency. Examples include Sodium (Na), Iron (Fe), etc.

A nonmetal is a chemical element that typically doesn't have a lot of metallic characteristics; examples include colourless vapours and glossy solids. They are usually bad conductors of heat and electricity and also have a high reduction potential. Examples include Chlorine (Cl), Carbon (C), etc.

A type of chemical element known as a metalloid has a majority of properties that fall between those of metals and nonmetals, or that are a combination of both. Examples include Antimony (Sb), Arsenic (As), etc.