Carbon is a non-metal. It exists
as several different allotropes. Soot, graphite and diamonds are all
composed of the same kind of atom ie carbon. The difference in their
properties is because the atoms are bonded in different ways. In graphite,
the atoms of carbon are arranged into sheets. Graphite can be used as a
lubricant. In diamonds, the atoms of carbon are bonded together into a
three dimensional solid. This makes diamond a very hard substance.
Silicon is a non-metal. It is used in
the manufacture of silicon chips. A very large crystal of silicon can be used to
make a chip by adding a small amount of another element.
