Sulfur has an atomic number of 16 what is the ground-state electron configuration of sulfur

1s2 2s2 2p6 3s2 3p4

Explanation:

Since the atomic number for sulfur is 16, we have 16 electrons to organize in the different orbitals, thus, we start with the first level and his orbital (1s) until the 3rd level and his p orbital. The orbital p can have 6 electrons at most but, in this case we have already located 12 electrons, just need 4 electrons for the p orbital in the 3rd level

so, the ground-state electron configuration of sulfur is

1s2 2s2 2p6 3s2 3p4

1s2 2s2 2p6 3s2 3p6

since it's grounded you add 2 more electrons to make it stable and it becomes [S]2-