The correct option is (c).
Explanation
Metalloids (or semi-metals) are a specific group of chemical elements in the periodic table that exhibit physical and chemical properties intermediate between those of metals and non-metals. They are located along the "zigzag" line that separates metals from non-metals.
- Statement 1 is Incorrect: Metalloids are pure chemical elements, not mixtures. A mixture of two or more metals, or a metal and a non-metal, is typically referred to as an alloy (e.g., steel or bronze). Metalloids occupy specific positions in the periodic table and have distinct atomic structures.
- Statement 2 is Correct: Common examples of metalloids include Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), and Polonium (Po). Silicon is widely used in the electronics industry due to its semiconductor properties.
- Statement 3 is Correct: Metalloids possess properties of both metals and non-metals. For example, they may have a metallic luster (like metals) but are brittle and poor conductors of electricity at room temperature (like non-metals). However, their conductivity often increases with temperature, making them excellent semiconductors.
Key Takeaway: Metalloids are distinct elements (e.g., Silicon, Germanium) defined by their intermediate properties and semiconductor behavior, whereas alloys are physical mixtures of elements.