### Rydberg's Equation

Posted: **Mon Oct 22, 2018 3:36 pm**

by **Tamera Scott 1G**

Is the equation En=-hR/n^2 the same as 1/λ= R(1/I^2-1/j^2), with I being the lower energy level and j being the higher energy level? If so, why isn't Planck's constant used in the second equation?

### Re: Rydberg's Equation

Posted: **Mon Oct 22, 2018 3:41 pm**

by **Chem_Mod**

Rydberg's equation can be derived from the En equation. Dr. Lavelle would like you to use the difference in energy to approach electron transition problem instead of just plugging in numbers. Energy difference is Ef-Ei = -hR/nf^2+hR/ni^2 = hR(-1/nf^2+1/ni^2). The energy is transmitted in the form of a photon, which as energy E=hv. As a result, by equating E = hR(-1/nf^2+1/ni^2) = hv, you can cancel out the Planck's constant.