SSC CGL 9 Aug 2015 Shift 2 Paper

The electronic configurationof helium atom is $1{\mathit{s}}^2$; it has twoelectrons. When helium atomloses one electron, it becomespositive ion with +1 charge;when it loses two electrons, itbecomes positive ion with +2charge on it ($\mathit{H}{\mathit{e}}^{2+}$). An alphaparticle is identical to a heliumatom that has beenstripped of its two electronsand is represented as $\mathit{H}{\mathit{e}}^{2+}$.