The reaction involves the formation of various compounds in a stepwise manner:

Phosphorus (P) reacts with Oxygen (O) to form Phosphorus Pentoxide (P2O5)Phosphorus Pentoxide (P2O5) undergoes a further reaction (represented by X) to convert into Sodium Phosphate (Na3PO4)Sodium Phosphate (Na3PO4) then reacts with Calcium ions (Ca) to form Calcium Phosphate (Ca3(PO4)2)