1. Energy of an atom
Bohr proposed to calculate energy you use the following equation
However, we also know that
Using substitutions, we get
Simplifying this equation, we get

2. Energy of an atom (cont.)
we also know that
Substituting, we come up with
Simplifying this, our final equation becomes
In this equation, m represents the mass of 1 Hydrogen atom, z the atomic number, e that charge of an electron, n as the energy level, and ħ=6.626*10^-34 j*s/2π.

3. Energy Of an Electron an Photon
Using the equation
we can obtain the
Energy of an electron in a specific energy level by substituting that level for n in the equation.
In a 3 energy level atom, the electron can emit a photon of 3 different energies, E1-E2, E1-E3, and E2-E3. These represent the changes in energy between levels. Actual energies can be scene in the table.
Energy of eletron(j)
N (energy level)
5.23*10^-67 1
2.61*10^-67 2
1.74*10^-67 3
Energy of a photon (j)
Energy level
2.62*10^-67
E1-E2
3.49*10^-67
E1-E3
8.70*10^-68
E2-E3