Metalloids are elements that have properties of both metals and non-metals. They are also known as semi-metals. Examples of metalloids include:

• Boron (B)
• Silicon (Si)
• Germanium (Ge)
• Arsenic (As)
• Antimony (Sb)
• Tellurium (Te)
• Polonium (Po)

Metalloids have a metallic appearance and are very hard and brittle. They tend to behave as semiconductors and are not typically used for mechanical applications. However, they can be introduced into other metals to form alloys, such as antimony mixed with lead to form antimonial lead alloys that are used in ammunition.