# Simple Question Regarding Bohr Atom Model

1. Oct 7, 2014

### Vishera

From Wikipedia, the following diagram explains the energy emitted when an electron jumps from a higher-energy shell to a lower-energy shell:

I already know that the energy of a single photon is equal to $hf$ and in this diagram, $\Delta E=hf$. Does that mean that $\Delta E$ is only one photon?

2. Oct 7, 2014

### Staff: Mentor

Yes, a "downward" transition between two energy levels produces a single photon.

3. Oct 7, 2014

### Staff: Mentor

It does not have to, but this is the typical case, yes.