The ionization energies $\left({\mathrm{IE}}_1\text{ to }{\mathrm{IE}}_2\right)$ of ‘s’ and / or ‘p’ block elements (X, Y and Z) are given below.

	${\mathrm{IE}}_1(\mathrm{kJ} {\mathrm{mol}}^{-1})$	${\mathrm{IE}}_2(\mathrm{kJ} {\mathrm{mol}}^{-1})$	${\mathrm{IE}}_3(\mathrm{kJ} {\mathrm{mol}}^{-1})$	${\mathrm{IE}}_4(\mathrm{kJ} {\mathrm{mol}}^{-1})$	${\mathrm{IE}}_5(\mathrm{kJ} {\mathrm{mol}}^{-1})$
X	1086	2353	4620	6223	37830
Y	800	1427	3060	25030	32830
Z	496	4562	6910	9543	13350

The number of valence electrons in X, Y and Z are