The following parameter is the same for all hydrogen-like atoms and ions in their ground state.

Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Bohr model to this atom. The longest wavelength photon that will be emitted has wavelength $\lambda$ (given in terms of the Rydberg constant $R$ for the hydrogen atom) equal to:

In the Bohr model of a hydrogen atom,the centripetal force is furnished by the Coulomb attraction between the proton and the electron. If ${a_0}$ is the radius of the ground state orbit,$m$ is the mass,$e$ is the charge on the electron,and ${\varepsilon _0}$ is the vacuum permittivity,the speed of the electron is:

The de-Broglie wavelength associated with the electron in the $n = 4$ level is

The acceleration of an electron in the first orbit of the hydrogen atom $(Z = 1)$ is

When the electron orbiting in a hydrogen atom in its ground state moves to the third excited state,the de-Broglie wavelength associated with it