Why are metalloids unique?
Metalloids are unique because they have properties of both metals and non-metals.
For example, boron acts as a nonmetal when it reacts with sodium, but it acts as a metal when it reacts with fluorine.
Silicon has a metallic lustre, but it is a poor conductor and is brittle
Most metals have a characteristic lustre and are good conductors of heat and electricity.
Most metalloids have a metallic lustre but are poor conductors of heat and electricity.
Most nonmetals have a dull appearance and are poor conductors of heat and electricity.