Chemistry

Question Analysis
This question tests the student's ability to arrange elements in order of increasing atomic radius based on their positions in the periodic table.

Key Concept Explanation
Atomic radius generally decreases as you move from left to right across a period and increases as you move down a group.

Step-by-step Solution
1. Identify the elements: O (oxygen), S (sulfur), Se (selenium), F (fluorine).
2. Recall the trend for atomic radius: it decreases from left to right across a period and increases down a group.
3. Arrange the elements in order of increasing atomic number: F (9), O (8), S (16), Se (34).
4....