How many unpaired electrons are there in an atom of sulfur in its ground state?
A) 1
B) 2
C) 4
D) 0
E) 3

Question

Quizplus · Accepted Answer

The atomic number of sulfur is 16. Its electron configuration in ground state is 1s^22s^22p^63s^23p^4. It has six valence electrons in the outermost shell (3s^23p^4). Each p orbital can hold up to two electrons, and sulfur has four p orbitals. Of these four, two are fully occupied with two electrons each (3p^2 and 3p^3), and the remaining two have one electron each (3p^1 and 3p^4). These two unpaired electrons make sulfur a free radical, which can engage in chemical reactions with other atoms or molecules to form chemical compounds. Therefore, there are two unpaired electrons in an atom of sulfur in its ground state.

How Many Unpaired Electrons Are There in an Atom of Sulfur