Name : Topic 12 Handout de Broglie, Schrodinger, Heisenberg
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Name : ___________________________________ Topic 12 Handout de Broglie, Schrodinger, Heisenberg, Radioactive decay II 1. State the de Broglie hypothesis . Use formulas in your explanation. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 2. Explain the major differences between the Bohr and Schrodinger Model of the Atom. Use drawings in your explanation. Drawings: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 1 3. Explain the Heisenberg Uncertainty Principle. Give an example: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 4. Nuclear energy levels Example 1 : Calculate the energy released during gamma decay reaction below: Fig. 6.4 below shows the lowest nuclear energy levels of the magnesium nucleus 24 Mg 12 2 Example 2 Fig 6.5 shows an energy level of plutonium and a few of the energy levels of uranium 242 238 Pu 94 U 92 Calculate the energy released during alpha decay for both alpha particles: Alpha particle 1 ( top graph) : Alpha particle 2 ( bottom graph) : 3 Write the decay reaction for the example above: 242 Pu 94 Tsokos Q1 p. 410 4 Example The following are statements concerning radioactive decay. I. Alpha particles have discrete energies. II. The beta-energy spectrum is a broad continuous distribution of energies. III. Gamma rays are emitted with discrete energies. Which statement(s) is(are) evidence for the existence of nuclear energy levels? A. I only B. II only C. III only D. I and III only Explain: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 5. State the Radioactive Decay Law and explain what the formula stands for: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Formula: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 5 6. IB Exam May 2010 B3 B3. This question is about radioactive decay. (a) The decay constant for a particular isotope is λ = 0.048 s–1. A sample of the isotope initially contains 2.0 x 1012 nuclei of this isotope. (i) Define decay constant. (ii) Estimate the number of nuclei that will decay in the first second. 7. TOPIC 12 NEW – Pair Production and Annihilation Summarize this section: ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 6 8. Use this formula: h xp 4 (The Heisenberg uncertainty principle for position-momentum) uncertainty in position = uncertainty in momentum. check solution on next page 7 8
