Question

which of the following has the smallest atomic radius? a b. b ga c f d n e al

Explanation:

Step1: Recall atomic - radius trend

Atomic radius decreases across a period (from left to right) and increases down a group (from top to bottom) in the periodic table.

Step2: Locate elements in periodic table

B (boron), N (nitrogen), and F (fluorine) are in the second - period. B is in group 13, N is in group 15, and F is in group 17. Ga (gallium) is in the fourth - period, group 13 and Al (aluminum) is in the third - period, group 13.

Step3: Compare elements in the same period

Among B, N, and F in the second - period, F has the smallest atomic radius due to the increasing effective nuclear charge from left to right across the period.

Step4: Compare with elements in other periods

Ga and Al are in lower periods than B, N, and F, so they have larger atomic radii.

Answer:

C. F