Structure Of Atom

The electron in the \(\mathrm{n}^{\text {th }}\) orbit of \(\mathrm{Li}^{2+}\) is excited to \((\mathrm{n}+1)\) orbit using the radiation of energy \(1.47 \times 10^{-17} \mathrm{~J}\) (as shown in the diagram). The value of \(\mathrm{n}\) is ___________

Given: \(\mathrm{R}_{\mathrm{H}}=2.18 \times 10^{-18} \mathrm{~J}\)