What term describes elements with properties between metals and nonmetals?

• A. Metalloids
• B. Halogens
• C. Transition metals
• D. Noble gases

Answer: (A)

Metalloids are elements with properties between metals and nonmetals. They often look metallic but behave chemically like nonmetals and can act as semiconductors, with electrical conductivity that can be adjusted by temperature or impurities. On the periodic table they form a dividing line between metals and nonmetals, including elements such as boron, silicon, germanium, arsenic, antimony, tellurium, polonium, and sometimes astatine. This mix—metallic-like appearance combined with nonmetallic behavior and semiconductor qualities—explains why they’re so important in electronics. The other groups don’t fit this concept: halogens are highly reactive nonmetals, transition metals are true metals with typical metallic properties, and noble gases are inert nonmetals with full electron shells.