Final answer:
Sulfur's electron configuration is 1s²2s²2p¶3s²3p´ and chlorine's is 1s²2s²2p¶3s²3p⁵, due to their positions in the periodic table with 16 and 17 electrons respectively.
Step-by-step explanation:
The electron configuration of sulfur (S), which has 16 electrons, is 1s²2s²2p¶3s²3p´. It ends with the 3p´ configuration because sulfur is in the third period and the 16th position on the periodic table. For chlorine (Cl), with 17 electrons, the electron configuration is 1s²2s²2p¶3s²3p⁵, reflecting its place directly after sulfur in the third period of the periodic table, thus having one more electron in the 3p subshell.