Task 4.9
The average kinetic energy of an electron in an unexcited hydrogen atom is 13.6 eV. Calculate
The De Broglie wavelength of an electron.

Task 4.19
The average lifetime of the excited state of the atom is 12 ns. Calculate the minimum
The uncertainty of the wavelength? = 0.12 μm of the radiation upon the transition of the atom to the ground state.
Task 4.29
The particle lies in an infinitely deep one-dimensional potential well of width l in the main
Condition. Find the ratio of the probabilities of finding the particle in the range from 0 to l / 3 and from l / 3 to 2 l / 3.

Task 4.39
When the electron passes through the copper atom from the M layer to the L layer, beams with a wavelength of 1.2 nm are emitted.
Calculate the screening constant in the Moseley formula.

Task 4.49
How many atoms 22286 Rn decay per day into 1 g of this isotope?
PROBLEM 4.59
Calculate the energy of the nuclear reaction 21 H + 31 H-> 42 He + n.
Task 4.69
What number of free electrons in a metal takes an average level with an energy equal to the energy
Fermi?
Task 4.79
Determine the impurity conductivity of germanium containing indium with a concentration of 1 * 1022 m-3 and
Arsenic with a concentration of 6 • 1021 m-3. The mobility of electrons and holes for germanium, respectively
Is 0.45 and 0.35 m2 / (V • s).