Calculating Electron Transmission for H-atom

[tessadalke]

For the example he did in class:

Calculate the freq of light emitted by a hydrogen atom when an electron makes a transition from the fourth to the second principal quantum level. En=-hR/n^2

He had E4= -1/16hR and E2=-1/4hR

Can someone tell me where he got -1/16 and -1/4?

[Samantha Man 1L]

So since the equation has a denominator of n^2, you take the initial n value which is four (initial quantum level) and square it so you get -1/16 and then you take the final n value which is two (final quantum level) and square that also so you get -1/4.

[Jaedyn_Birchmier3F]

Since we are dealing with the energy levels n=4 and n=2 you have to plug the n values into the equation and as you stated the equation has an n squared on the bottom. N= 4 squared would be 16 and n=2 squared would be 4. This is how those numbers in the denominater came about.