Final answer:
The ionic compound formed between the sodium cation (Na+) and the sulfide anion (S²⁻) has the formula Na2S, which signifies that there are two sodium ions for every sulfide ion to balance the overall charge.
Step-by-step explanation:
To predict the formula of the ionic compound formed between the sodium cation (Na+) and the sulfide anion (S²⁻), we consider the charges on each ion. Sodium, with a 1+ charge, and sulfide with a 2- charge need to balance each other out. This balance is achieved by combining two sodium ions for every one sulfide ion to form the ionic compound.
Using this information, the correct formula for the compound is Na2S. This indicates that there are two sodium cations for every one sulfide anion, resulting in a neutral compound.
The formula for the ionic compound formed between the sodium cation, Na+, and the sulfide anion, S²-, is Na+2S2-. The 2+ charge on the sodium cation is balanced by two sodium cations (Na+), and the 2- charge on the sulfide anion is balanced by one sulfide anion (S2-). So the formula for this ionic compound is Na2S.