## Rydberg's Equation

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

WilliamNguyen_4L
Posts: 65
Joined: Fri Sep 28, 2018 12:28 am

### Rydberg's Equation

Why in the equation ΔE=Rhc((1/nf^2)−(1/ni^2)) is nf always the smaller of the two energy levels?

Timothy_Yueh_4L
Posts: 57
Joined: Fri Sep 28, 2018 12:28 am

### Re: Rydberg's Equation

Since it is 1/nf^2 – 1/ni^2, the resulting energy value is positive if nf is the smaller value. Since delta E represents the change of energy, which tends to be a positive value, nf needs to be the smaller primary quantum number in order to satisfy that condition.