The chemical compound formed between lithium and sulfur is lithium sulfide, with the chemical formula Li₂S.

Here's why:

* Lithium (Li) is a metal in group 1 of the periodic table, meaning it has a +1 charge when it forms an ion.

* Sulfur (S) is a nonmetal in group 16 of the periodic table, meaning it has a -2 charge when it forms an ion.

* To achieve a neutral compound, you need two lithium ions (+1 each) to balance the charge of one sulfide ion (-2).