Nonmetals and Metalloids

Nonmetals are far less uniform than metals. Oxygen is a gas, bromine is a liquid at room temperature, and carbon in its diamond form is the hardest known natural material.

Metalloids like silicon, germanium, and arsenic are the chameleons. Silicon is a poor conductor at room temperature but becomes a better conductor when heated — the opposite of metals. This property makes silicon perfect for semiconductors, the foundation of all modern electronics.