Select the element(s) that will have ONE unpaired electron in the p orbital. Ca

N

B

Ar

Br

The element B will have ONE unpaired electron in the p orbital.

Explanation:

The electronic configuration of each given element is as follows.

Atomic number of calcium (Ca) is 20.

Ca:

Atomic number of nitrogen (N) is 7.

N:

Atomic number of boron (B) is 5.

B:

Atomic number of argon (Ar) is 18.

Ar:

Atomic number of bromine (Br) is 35.

Br:

Therefore, boron is the only element that have one unpaired electron in the p-orbital.

Thus, we can conclude that element B will have ONE unpaired electron in the p orbital.