1. Convert grams to moles:

* Fluorine (F): 259.2 g F / 19.00 g/mol F = 13.64 mol F

* Carbon (C): 40.8 g C / 12.01 g/mol C = 3.40 mol C

2. Find the mole ratio:

* Divide the number of moles of each element by the smallest number of moles:

* F: 13.64 mol / 3.40 mol = 4.01 ≈ 4

* C: 3.40 mol / 3.40 mol = 1

3. Write the empirical formula:

* The mole ratio of F to C is approximately 4:1.

* Therefore, the empirical formula is CF₄.