# Homework Help: Lyman series

1. Feb 20, 2006

### Tony11235

How am supposed to calculate the five longest wavelengths of the Lyman series? What values of n are used? I see how you arrive at a definite limit as n goes to infinity, but the five longest? Sort of a dumb question.

2. Feb 20, 2006

### phucnv87

Remember that

$$\Delta E=\frac{hc}{\lambda}$$

$$\Longrightarrow \lambda=\frac{hc}{\Delta E}$$

$$\Delta E=E_{initial}-E_{final}$$

To get the longest wavelength, $$\Delta E$$ must be at minimum value