Final answer:
Chlorine (Cl) has the smallest atomic radius among the given options
Step-by-step explanation:
The atomic radius refers to the size of an atom, which is measured from the nucleus to the outermost electron shell. As we move across a period in the periodic table from left to right, the atomic radius decreases. This is because the number of proton increases, which attracts the electrons more strongly and pulls them closer to the nucleus.
In the given options, chlorine (Cl) has the smallest atomic radius because it is located in Group 17 (Group 7A), which is the furthest right in the periodic table. The atomic radius of chlorine is smaller compared to the other elements in the options.