Based on their positions on the periodic table, which of the following elements is classified as a metalloid?

• A. Fe
• B. Na
• C. Cl
• D. Si

Answer: (D)

Verified step by step guidance

1. Understand that metalloids are elements with properties intermediate between metals and nonmetals, and they are typically found along the 'stair-step' line on the periodic table separating metals and nonmetals.
2. Identify the positions of the given elements on the periodic table: Fe (iron) is a transition metal, Na (sodium) is an alkali metal, and Cl (chlorine) is a halogen nonmetal.
3. Recall that Silicon (Si), although not listed in the options here, is located along the metalloid line in group 14 and period 3, which is characteristic of metalloids.
4. Compare the properties and positions of the elements: since Fe, Na, and Cl are clearly metal or nonmetal, and Si is known to be a metalloid, Si is the correct classification for a metalloid.
5. Conclude that based on periodic table positions and element properties, Si is classified as a metalloid, while Fe, Na, and Cl are not.