Question

. A photon ionises a hydrogen atom from the ground state. The liberated electron recombines with a proton into the first excited state, emitting a 4 A photon Find the energy of the free electron, and on the energy of the original photon
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Answer 1

Explanation:

Conservation of energy requires that the 15.0eV photon energy first provides the ionization energy to unbind the electron, and then allows any excess energy to become the electron's kinetic energy.

The kinetic energy in this case is 15.0eV−13.6eV=1.4eV