wavelength range order in formula

[Sisam Bhattarai 2C]

When solving for the wavelength range with the equation v=R[1/n1^2-1/n2^2] when n=5, how do you find the four different wavelengths and which would be initial for the second pair, because 5 is constant. So, wouldn't n1=5?

[awang3I]

Yes, n₁ would be 5. To find the wavelength range, solve the equation v=R[1/n1^2-1/n2^2] separately for when n₂ = 4 and when n₂ = 1. This will give you both the longest and shortest possible frequencies which you can use to find the longest and shortest possible wavelengths.