The correct composition of the ionic compound lithium sulfide (Li2S) is 2 Li+ ions and 1 S2- ion.
In this compound:
- Lithium (Li) has a +1 charge, so two lithium ions contribute a total charge of +2.
- Sulfide (S) has a -2 charge as it gains two electrons to achieve a stable electron configuration.
Thus, the overall charge balance in Li2S is neutral, with 2 Li+ ions balancing out the single S2- ion.