Emission transitions in the Paschen series end at orbit $\mathrm{n}=3$ and start from orbit $\mathrm{n}$ and can be represented as $\mathrm{v}=3.29\times {10}^{15} \left(\mathrm{Hz}\right) \left[\frac{1}{3^2}–\frac{1}{{\mathrm{n}}^2}\right]$. Calculate the value of n if the transition is observed at $1285 \mathrm{nm}$. Find the region of the spectrum.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. If any of these combination(s) has/have the same energy lists:

1. $\mathrm{n}=4, \mathrm{l}=2, {\mathrm{m}}_{\mathrm{l}}=–2, {\mathrm{m}}_{\mathrm{s}}=–1/2$
2. $\mathrm{n}=3, \mathrm{l}=2, {\mathrm{m}}_{\mathrm{l}}=1, {\mathrm{m}}_{\mathrm{s}}=+1/2$
3. $\mathrm{n}=4, \mathrm{l}=1, {\mathrm{m}}_{\mathrm{l}}=0, {\mathrm{m}}_{\mathrm{s}}=+1/2$
4. $\mathrm{n}=3, \mathrm{l}=2, {\mathrm{m}}_{\mathrm{l}}=–2, {\mathrm{m}}_{\mathrm{s}}=–1/2$
5. $\mathrm{n}=3, \mathrm{l}=1, {\mathrm{m}}_{\mathrm{l}}=–1, {\mathrm{m}}_{\mathrm{s}}=+1/2$
6. $\mathrm{n}=4, \mathrm{l}=1, {\mathrm{m}}_{\mathrm{l}}=0, {\mathrm{m}}_{\mathrm{s}}=+1/2$