How many atoms does calcium fluoride=CaF2 have??

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .

Deposition  is  change of state has the wrong energy change listed 

Caso4(s) < > ca+2 + so4^-2 ksp = [ca+2][so4^-2] = 2.4 x 10^-5 = [0.20][so4^-2] [so4^-2] =1.2 x 10^-4 ag2so4(s) ,> 2ag+ + so4^-2 ksp = [ag+]^2[so4^-2] = 1.5 x 10^-5 = (0.30)^2[so4^-2] [so4^-2] = 1.5 x 10^-5/0.09 = 1.7 x 10^-4 caso4 would precipitate first since it requires less so4^- to form a saturated solution.  i believe this is right, i hope it !  

The answer would have to be  reduce human impact on the environment