I am using EE representing * 10 ^. There should be that button at your scientific calculator.
1 mol = 6.02EE23 [means 6.02 * 10^23)
Ca = 40.078 grams
F = 18.998 grams
CaF2 = 78.074 grams
2.82EE22 CaF2 particles * (1 mol CaF2 / 6.02EE23 CaF2 particles) * ( 78.074g CaF2 / 1 mol CaF2)
= (2.82EE22 CaF2 particles * 1 mol CaF2 * 78.074g CaF2) / (6.02EE23 CaF2 particles * 1 mol CaF2)
= (2.82EE22 * 78.074g CaF2) / (6.02EE23)
= approx 3.66g CaF2 (Sig figs! I hate them!)
