What would the molecular formula be if lithium and sulfur reacted to form a neutral compound?

A. Li2S2

B. LiS2

C. LiS

D. Li2S

D would be your answer.

Lithium has a valence electrons of one.

Sulfur has two valence electrons.

Now you cross it these numbers and bring them down.

D

Explanation:

Lithium has one valence electron, so it has one to give away to have an outer shell of 8.

Sulfur has 6 valence electrons, so it needs 2 to get an outer shell of 8.

If we have two Li, that means sulfur will get 2 e - and Li will give away 2 e-, so the formula is Li₂S.