let us assume that we ave started with 100 g of compound and the compound on decomposition gives 67.62 g ( 67.62%) of Uranium and 32.38 g ( 32.38%) of fluorine.
Step II Calculate the number of moles of each element \
Step III ; Calculating the simple whole ratio
U = 0.284 / 0.284 = 1 and F = 1.70 / 0.284 = 6
the empirical formula is