Chapter 39, Problem 1Q

An electron is in the nth Bohr orbit of the hydrogen atom. (a) Show that the period of the electron is T = n3t0 and determine the numerical value of t0. (b) On average, an electron remains in the n = 2 orbit for approximately 10 ms before it jumps down to the n = 1 (ground-state) orbit. How many revolutions does the electron make in the excited state? (c) Define the period of one revolution as an electron year, analogous to an Earth year being the period of the Earth’s motion around the Sun. Explain whether we should think of the electron in the n = 2 orbit as “living for a long time.”

(a) What quantum numbers are needed to give a complete description of the quantum state of an electron in an atom? (b) List the value of each of the quantum numbers mentioned in (a) for each of the electrons in a neutral strontium atom in its ground state.

The electron of a hydrogen atom is in an orbit with radius of 8.46 Å (1 Å = 10-10 m), according to the Bohr model. Which of the following statements is correct?  a) The total energy of the orbit is –13.6 eV, and the kinetic energy is +13.6 eV. b) The total energy of the orbit is –0.85 eV, and the potential energy is –1.70 eV. c) The total energy of the orbit is –0.85 eV, and the potential energy is +1.70 eV. d) The total energy of the orbit is –0.85 eV, and the potential energy is –0.85 eV. e) The total energy of the orbit is –3.40 eV, and the potential energy is –6.80 eV.