Answer: 2 moles of
will be formed.
Explanation:
To calculate the moles :

The balanced chemical equation is:
According to stoichiometry :
2 moles of
give = 2 moles of 
Thus 2 moles of
give =
of 
Thus 2 moles of
will be formed.
Moles of ca3(po4)2 = 23.7 / 310.17 = 0.076
moles of (PO4)3- = 0.076 x 2 = 0.152
now, no. of ions = 0.152 x 6.022 x 10^{23}
= 9.2 x 10^{22}
True because in a solid particles dont move so it wouldn't be in a constant motion.