[محمد عبد السلام عواد]

number of moles (iron) = 63.63\55.8 = 1.14
number of moles (sulpher) = 36.47 \32 = 1.14
the two numbers resulted from the dividing of the percent of element on it's atomich mass is your number of moles
1 : 1




so the empirical formula is FeS