Well, we use the "aufbau principle", and for sulfur, Z=16....
Explanation:
And thus.....1s^(2)2s^(2)2p^(6)3s^(2)3p^4; this distributes the 16 electrons appropriately. Given this configuration, sulfur commonly forms sulphide anion, i.e. S^(2-). Can you give the electronic description for S^(2-). What other element shares this configuration?