Question: how many moles of molecules are there in 38g of fluorine f2?
Answer: Molar mass of F2 is 38 g. How many atoms are present in 0.147 mole of F2? One molecule of F2 contains 2 atoms of fluorine. So, 0.147 moles will contain 0.147 X 2 X 6.023 X 1023 = 1.76 X 1023 atoms of flourine.