Answer:
The ground state configuration for the negative ion of a halogen. ... A possible excited state electronic configuration. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^1 6s^1. Its symbol is the double solid lin, // or ||, in a cell diagram.
AC2
A will lose 2
C will gain 1
Need two Cs to match A
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}