All Problems

Wave Properties of particles. Schrodinger Equation.

Problem 6.92

The wave function of an electron of a hydrogen atom in the ground state takes the form \(\psi(r)=A \mathrm{e}^{-r / r_{1}},\) where \(A\) is a certain constant, \(r_{1}\) is the first Bohr radius. Find: (a) the most probable distance between the electron and the nucleus: (b) the mean value of modulus of the Coulomb force acting on the electron; (c) the mean value of the potential energy of the electron in the field of the nucleus.

Reveal Answer
\(6.92 .\) (a) The probability of the electron being at the interval \(r, r+d r\) from the nucleus is \(d P=\psi^{2}(r) 4 \pi r^{2} d r .\) From the condition for the maximum of the function dP/dr we get \(r_{p r}=r_{1} ;\) (b) \(\langle F\rangle=2 e^{2} / r_{1}^{2}\) (c) \(\langle U\rangle=-e^{2} / r_{1}\)