The total energy of an electron in the first excited state of hydrogen is about -3.4 eV . Its kinetic energy in this state is

Step-by-step solution

The kinetic energy is equal to the negative of total energy. Kinetic energy of electron K= Z e^2 8 ₀ r Potential energy of electron U=- 1 4 ₀ Z e^2 r :. Total energy E=K+U= Z e^2 8 ₀ r - Z e^2 4 ₀ r aligned & or E=- Z e^2 8 ₀ r & or E=-K & or K=-E=-(-3.4)=3.4 eV & aligned