Total number of ions from the following with noble gas configuration is ____. Sr^2+(z=38), Cs^+(z=55), La^2+(z=57), Pb^2+(z=82), Yb^2+(z=70) and…

Total number of ions from the following with noble gas configuration is $\displaystyle \_\_\_\_$. $\displaystyle \mathrm{Sr}^{2+}(z=38), \mathrm{Cs}^{+}(z=55), \mathrm{La}^{2+}(z=57), \mathrm{Pb}^{2+}(z=82), \mathrm{Yb}^{2+}(z=70)$ and $\displaystyle \mathrm{Fe}^{2+}(z=26)$