Question

5a) Positronium is a bound state of an electron and a positron. What is the energy of the photon emitted in transitions of positronium from the first excited state to the ground state? (A) 1.7 eV , (B) 5.1 eV , (C) 6.8 eV , (D) 13.6 eV, (E) 20.4 eV

5b) A new hydrogen-like atom is discovered where the particle orbiting the proton has mass 2me and charge 2e, where me and e are the mass and charge of the electron, respectively. What is the binding energy of this atom, in terms of the binding energy E of ordinary hydrogen?

(A) E/2, (B) E , (C) 2E, (D) 4E, (E) 8E

5c) The Bohr model is inconsistent with the modern picture of quantum mechanics because it predicts which of the following?

(A) The electron will not lose energy as it orbits the nucleus., (B) The electron is confined to distinct energy shells., (C) Angular momentum of the atom is quantized., (D) The ground state has nonzero angular momentum., (E) The energy levels go as 1/n2 , where n is the principal quantum number.

Answer 1