Correct Option
The correct option isSilicon
Explanation
Elements in the Modern Periodic Table are classified into metals, non-metals, and metalloids based on their physical and chemical properties. Metalloids (or semi-metals) are elements that exhibit characteristics intermediate between those of metals and non-metals. They are typically located along the "zigzag" line separating metals from non-metals in the p-block.
Option Analysis
- Sodium (Na): Incorrect. Sodium is an alkali metal found in Group 1. It exhibits typical metallic properties such as high reactivity, malleability, and electrical conductivity.
- Silicon (Si): Correct. Silicon is a metalloid. It possesses properties of both metals (e.g., lustrous appearance) and non-metals (e.g., brittleness). Crucially, it acts as a semiconductor, meaning its electrical conductivity increases with temperature, a property distinct from typical metals.
- Iodine (I): Incorrect. Iodine is a non-metal belonging to the Halogen group (Group 17). While it has a lustrous appearance, it is a poor conductor of heat and electricity.
- Silver (Ag): Incorrect. Silver is a transition metal. It is known for having the highest electrical and thermal conductivity of all elements.
Key Takeaway: The primary metalloids in the periodic table include Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), and Polonium (Po). These elements are essential in the semiconductor industry.