Answer:
K2 Cr2 O7 is the empirical formula
Step-by-step explanation:
Assume we have 100 g of the compound, because it makes the number of grams equal to the percentage.
Then convert grams of each element into moles
Then divide the moles of each element by the smallest number of moles attained to get the whole number mole ratios of the empirical formula
However, if you don't get whole numbers when you divide by the smallest number of moles, then multiply all moles by one common factor that makes them all whole numbers.