Which group has properties between metals and nonmetals?

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

Answer: (A)

Metalloids are elements with properties between metals and nonmetals. They sit along the boundary between metals and nonmetals on the periodic table and often look metallic, yet their electrical conductivity is intermediate and can be controlled (for example, by temperature or adding impurities), making them useful as semiconductors in electronics. They tend to be brittle like nonmetals but can have some metallic luster, and their behavior bridges the two categories. Typical examples include silicon and germanium, along with others like boron and tellurium. This mixed set of characteristics is what sets metalloids apart from the other groups: alkali metals are highly reactive metals, halogens are reactive nonmetals, and noble gases are inert nonmetals.