Question

which element has the smaller atomic radius: potassium (k) or bromine (br)? potassium (k) bromine (br)

Explanation:

Step1: Recall atomic - radius trend

Atomic radius decreases across a period from left to right. Potassium (K) is in Group 1 and Bromine (Br) is in Group 17 of the same period (Period 4).

Step2: Compare positions

Since Br is to the right of K in Period 4, Br has a smaller atomic radius due to the increasing effective nuclear charge across the period.

Answer:

bromine (Br)