Non-metals

Oxygen, carbon, sulfur and chlorine are examples of non-metal elements. Non-metals have properties in common. They are:

  • dull (not shiny)
  • poor conductors of heat and electricity (they are insulators)
  • weak and brittle (they easily break or shatter when solid)

Most non-metals also have these properties:

  • they have a low density (they feel light for their size)
  • They are NOTsonorous (they do not make a ringing sound when hit)

Eleven non-metals are gases at room temperature, including oxygen and chlorine.

One non-metal, bromine, is a liquid at room temperature.

The other non-metals are solids at room temperature, including carbon and sulfur.

Reactions of non-metals

Non-metals react with oxygen to produce non-metal oxides. For example, sulfur reacts with oxygen to produce sulfur dioxide. The reaction can be represented by this word equation:

sulfur + oxygen → sulfur dioxide

Non-metal oxides react with bases and neutralise them. Some non-metal oxides dissolve in water and, when they do, they produce acidic solutions.

Diamond and graphite

Carbon is a solid non-metal element. Pure carbon can exist in very different forms. The most common two are diamond and graphite. The table shows some differences between them.

DiamondGraphite
Transparent and colourlessOpaque and black
HardSoft

Diamond is the hardest natural substance on Earth, but it is also very brittle and will shatter if hit with a hammer.

Graphite is unusual because it is a non-metal that conducts electricity.

Uncut diamonds with scoop and measurement gauge
Diamonds are used in jewellery and cutting tools