The modern electron configuration of sulfur (S) is:

1s² 2s² 2p⁶ 3s² 3p⁴

Here's how to understand it:

* 1s²: The first energy level (n=1) has one sublevel, the 's' sublevel, which can hold up to 2 electrons.

* 2s²: The second energy level (n=2) has two sublevels, 's' and 'p'. The 's' sublevel holds 2 electrons.

* 2p⁶: The 'p' sublevel in the second energy level can hold up to 6 electrons.

* 3s²: The third energy level (n=3) has two sublevels, 's' and 'p'. The 's' sublevel holds 2 electrons.

* 3p⁴: The 'p' sublevel in the third energy level has 4 electrons.

Important Note: This is the ground state electron configuration. Sulfur can have different electron configurations when it forms ions or excited states.