Question

Chapter 32: The Atom and the Quantum

1. In relation to the atom as a whole (in terms of mass, size, charge), how is the nucleus of an atom characterized?

2. What was Rutherford's famous gold foil experiment? (Provide a sketch.)

3. What conclusions were drawn from the results of this experiment? And how were these conclusions drawn?

4. In general, what kinds of clues to atomic structure were provided by atomic spectra at that time?

5. What is the Ritz combination principle?

6. What are the assumptions of the Bohr model?

7. How does the Bohr model explain the Ritz combination principle?

8. How are the spectral lines of an atom predicted from the energy levels of the atom? What is the underlying explanation of the existence of specific discrete spectral lines? (Provide a sketch.)

9. What determines the diameter of electron orbits in the Bohr model of the atom?

10. What fundamental force dictates the size of an atom?

11. What "waves" in Schrodinger's wave equation?

12. How is the wave function of quantum mechanics denoted, and what kind of quantity is it?

13. What is the probability function of an electron in an atom in a particular state, and what is this function in terms of the wave function of the electron in that state?

14. What does “tunneling” mean with regard to quantum mechanics?

15. How is the correspondence principle illustrated with respect to quantum mechanics and Newtonian physics?

Answer 1

1. The nucleus is the densest part of the atom, in terms of mass. The entire positive charge is contained within the nucleus. The nucleus of the atom is very very small. For a rough idea, if the atom were the size of a cricket stadium the nucleus would be the size of a peanut, this causes the high density.

2.

3. It was observed that most of the alpha particles passed through the foil without being reflected which suggested that the mass of the atom is concentrated in a very small part of it i.e. the nucleus.