_fe +
_s →
_fes
balance the equation

Fe + S → FeS

The equation is already balanced.

Explanation:

Chemical equation:

Fe + S → FeS

The equation is already balanced.

Chemical equation with physical state:

Fe(s) + S(s) → FeS(s)

Solid iron react with solid sulfur and produced iron(II) sulfide.

The charge on iron is +2 while on sulfur is -2, both cancel the effect of each other make the compound over all neutral.

One atom of iron loses its two electron and sulfur accept its two electron both complete the octet and get stable.

Iron is metal in this compound and sulfur is non metal.

b is the best answer for this question.