Majority of the elements are metals. Nonmetals usually located at the far right of the table. Between two extremes there exist elements which possess the chracteristics of both metals and nonmetals. These elements are called metalloids. They are roughly located at the transition between metals and nonmetals, towards the right side of the table. In our table, they are located at or near to the boundary shaded in gray and lime green.
Metals - They are usually solids, strong and hard at room temeprature. The notable exception is mercury, which is a liquid metal. They are generally shiny, silvery in appearance when freshly cut. Some metals tarnish when expose to air (due to reaction with oxygen in air). They are malleable, that is, can be worked (bent, hammer so on) into
a variety of shapes. They are also ductile, for example, can be drawn into wire. Metals are generally good conductors of heat and electricity.
Nonmetals - Can be solids (e.g. sulfur) , liquids (e.g. bromine) or gases (e.g. oxygen) at room temperature. With a few exception (such as carbon), nonmetals generally have low melting points. General appearance are usually dull and gases can be colorless. When solid, they are
usually brittle. They are also poor conductors of heat and electricity.
Metalloids - Elements that possess the characteristics between metals and nonmetals. For example, they are generally semiconductors, that is, a good conductor when compare with nonmetals but a poor conductor when compare with metals. These materials are often prepared to high purity grade for use in semiconductor electronic devices.