What are metalloids?

are that behave as metals as well as non-metals.

In some elements, especially the lower members of groups 14 to 17, have properties of both metals and non-metals. They are called semi-metals or metalloids.

Examples are silicon, germanium, arsenic, antimony, tellurium, and polonium.

Chemically, all elements that have a tendency to form positive ions by losing electron are metals. All metals are good conductors of heat and electricity.

Elements that tend to gain electrons and form negative ions are non-metals. All the gases are non-metals. They are poor conductors of heat and electricity.

At room temperature, metalloids are poor conductors of electricity. They become better conductors at higher temperatures, because more electrons become free to conduct.

Silicon is a metalloid. Like a metal, it has high melting and boiling points. It has a metallic lustre and is a good conductor of heat.

Unlike a metal, silicon is brittle and a poor conductor of electricity, and its conductivity increases with temperature.