Answer:
Potassium > Vanadium > Zinc > Bromine
Explanation:
The size of an atom can be difficult to estimate. It is measured in terms of the atomic radius.
It is the taken as half of the inter-nuclear distance between covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
The elements given all lie in the same period so their atomic radius decreases.