Molar mass of F2 is 38 g. How many atoms are present in 0.147 mole of F2?
1.76 Χ 1023 atoms
One molecule of F2 contains 2 atoms of fluorine.
1 mol of fluorine contains 2 X 6.023 X 1023 atoms
So, 0.147 moles will contain 0.147 X 2 X 6.023 X 1023 = 1.76 X 1023 atoms of flourine.