Grouping elements: metals, non-metals and metalloids
Elements can be grouped into three main categories: metals, non-metals and metalloids. These terms refer to the different properties of these elements in their pure forms. These properties have important applications in everyday life. See Image 1
Most of the elements on the periodic table are metals. Metals are solid at room temperature - with only one exception, mercury, which is a liquid at room temperature - and have very high melting and boiling points. Metals are shiny and malleable, which means they can easily be bent into shapes. See Image 2 They are also very good conductors of heat and electricity. Metals are very dense and ductile,which means they can be stretched into wires. Some common examples of metals are copper, iron and gold. Metals can be used in wires for conducting electricity, cookware, and jewellery, among other things.
Non-metals are not shiny, malleable or good conductors. Again, there is one exception to the last rule - carbon, a non-metal, can conduct electricity in some cases. Non-metals can be solid, liquid or gaseous at room temperature. Around half the non-metals are gases at room temperature. Non-metals tend to have low melting and boiling points. They are not ductile. Some common examples of non-metals are sulphur, oxygen and hydrogen. Non-metals are used for many things, including making fertiliser, bicycle frames and lubricants.
Some elements have properties of both metals and non-metals. These are called metalloids or semi-metals. A common metalloid is silicon. Silicon is slightly conductive of electricity, but it doesn't conduct heat. It also is brittle (or non-malleable) and non-ductile. There are eight metalloids on the periodic table: boron, silicon, arsenic, germanium, antimony, polonium, astatine and tellurium. They are often used in making computer parts. See Image 3
See video 'Metals'