10 minutes maximum! Can you do it in 5?

Constructive and destructive interference patterns can be produced with..

  • A. only photons.
  • B. only photons and electrons.
  • C. only electrons and protons.
  • D. photons, electrons and protons.

2. The formula E= hf can be used with..

  • A. only photons.
  • B. only photons and electrons.
  • C. only electrons and protons.
  • D. photons, electrons and protons.

3.The energy levels of electrons in a hydrogen atom can be calculated using the Bohr model.

Which of the following formulas can be used to calculate the energy released (as a photon) when an electron drops from n=2 to n=1?


4. For an electron orbiting the hydrogen nucleus, what is the quantity mvr equal to ?

  • A. The centripetal force required to maintain a circular orbit.
  • B. The angular momentum of the electron.
  • C. The energy of the electron.
  • D. The linear momentum of the electron at any point.

5.A high energy photon can instantaneously produce matter from energy through the process of pair production. An example of this is:

  • A. A photon producing a neutron and a proton.
  • B. A photon producing two neutrons.
  • C. A photon producing a proton and an electron.
  • D. A photon producing an electron and a positron.

6. For an electron to be trapped in the nucleus of an atom, its position must be known to an accuracy of about 10-15 m. This means the uncertainty in the momentum must be of the order of

  • A. 10-15 kg ms-1
  • B. 10-17 kg ms-1
  • C. 10-19 kg ms-1
  • D. 10-21 kg ms-1

7-10. An electron has kinetic energy Ee. It is trapped by two potential barriers of energy Eb as shown in this diagram.
Eb > Ee, so using classical physics, the electron cannot escape. However the electron still has a small chance of appearing on the other side of these barriers.


7. What is the name of this effect?

  • A. Quantum tunnelling.
  • B. Barrier jumping.
  • C. Wave function tunnelling.
  • D. Probability tunnelling.

8. How do the following changes affect the probability of the electron appearing on the other side of the barrier?

Increase the width W Increase the quantity (Eb-Ee)
no effect no effect
lower probability no effect
no effect lower probability
lower probability lower probability

9. Which of these is proportional to the probability of finding the electron at a particular location?

  • A. The wave function
  • B. The square of the wave function
  • C. The angular momentum
  • D. The square of the angular momentum

10. Which of these statements about the value of the wave function is correct?

Within the barrier Outside the barrier
zero at all points zero at all points
non-zero zero at all points
zero at all points non-zero
non-zero non-zero