What is the charge on the cation in the iconic compound Sodium Sulfide?

Sodium commonly forms a
+
I
ion.
Explanation:
And thus the chemical formula for sodium sulfide is
N
a
2
S
, i.e. two sodium ions are required to form a neutral salt with
S
2
−
.

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts