Which of the following has the largest atomic radius?

Correct option is A

The correct answer is (A) Iodine.

Explanation:

The atomic radius of an element is the distance from its nucleus to the outermost electron shell. In the periodic table:

1. Trends in Atomic Radius:
• Down a Group: The atomic radius increases because additional electron shells are added, increasing the size of the atom.
• Across a Period: The atomic radius decreases from left to right due to increased nuclear charge, which pulls electrons closer to the nucleus.
2. Comparison:
• Iodine (I): Located in Group 17 and Period 5. It has the largest atomic radius among the given elements because it is the heaviest halogen with the most electron shells.
• Fluorine (F): Located in Group 17 and Period 2. It has a small atomic radius due to fewer electron shells and a high effective nuclear charge.
• Chlorine (Cl): Located in Group 17 and Period 3. Its atomic radius is smaller than iodine but larger than fluorine.
• Oxygen (O): Located in Group 16 and Period 2. It has the smallest atomic radius among the given options because it is not only in the second period but also has a smaller atomic structure than halogens.