The following equation is not balanced:
Na
3
PO
4
+MgCl
2
?Mg
3
(PO
4
)
2
+NaCl
Part A
Notice that “PO
4
” appears in two different places in this chemical equation. PO
3?
4
is a polyatomic ion called phosphate . What number should be placed in front of Na
3
PO
4
to give the same total number of phosphate ions on each side of the equation?
?Na
3
PO
4
+MgCl
2
?Mg
3
(PO
4
)
2
+NaCl
Express your answer numerically as an integer.