State the number of atoms present in each of the following chemical species

(a) CO32-


(b) PO43–


(c) P2O5


(d) CO

(a) The number of atoms in CO32- = the atom of C + the atom of oxygen

= 1 + 3


= 4


(b) The number of atoms in PO43– = the atom of P + the atoms of oxygen


= 1 + 4


= 5


(c) The number of atoms in P2O5 = the atoms of P + the atoms of oxygen


= 2 + 5


= 7


(d) The number of atoms in CO = the atom of C + the atoms of oxygen


= 1 + 1


= 2


18