How many of the elements in the second row of the periodic table (li through ne) will have at least one unpaired electron in their electron configurations?

The second row of the periodic table consists of the elements:

Lithium (3)

Beryllium (4)

Boron (5)

Carbon (6)

Nitrogen (7)

Oxygen (8)

Fluorine (9)

Neon (10)

The number in the bracket shows the atomic number of the elements, which also indicates the number of electrons they have. We see that the odd numbered elements, Li, B, N and F will all have unpaired electrons. Therefore, 4 elements will have unpaired electrons in their electronic configuration.