What element in the second period has the largest atomic radius?

a. carbon

b. neon

c. potassium

d. lithium?

The correct option is D.

The elements in the second period are lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon. In the second period, the atomic radius of the elements decreases across the period, thus lithium has the highest atomic radius of 152 picometer while neon has the least [67 picometer].