What are metalloids in the Periodic Table?

Metalloids are the class of
elements in the Periodic Table of the Elements that
separate metals from non-metals. The elements on either side of the metalloids are
either metallic or non-metallic, while the metalloids contain properties of both. This
allows interesting chemical reactions as well as chemical combinations that are not seen
in true metals and true non-metals. For example, silicon is
a semi-conductor, which means that it does not fully conduct electricity like
copper, but can conduct electricity if the conditions are
correct; silicon is therefore useful in computers and other technology where a varying
conduction rate is important. Aluminium, which people
commonly think of as a metal because of its use in beverage cans, is actually a disputed
element; it is thought of as an "Other Metal" because of its non-metallic
properties.