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1.4: Concept Review Questions Chapter 1

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    344570
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    Concept Review Questions

    Section 1

    1. Which were the elements in the antique non-atomistic element theories?

    2. Explain the definition of the term “atom” as introduced by Leukippes and Demokrites.

    3. What does the law of the conservation of mass state?

    4. Who discovered the law of the conservation of mass?

    5. What obscured the discovery of the law of the conservation of mass for a long time?

    6. Explain why the discovery of the law of the conservation of mass was important for the development of atomic theory.

    7. What does the law of the constant compositions state?

    8. Who discovered the law of the constant compositions?

    9. What does the law of the multiple proportions state?

    10. Who discovered the law of the multiple proportions?

    11. Explain why the law of the multiple proportions can be explained by Dalton’s hypothesis.

    12. Explain what cathode rays are and how they are being produced.

    13. Explain how Thomson identified electrons in cathode rays.

    14. Explain why Rutherford’s gold foil experiment disproves Thomson’s atom model.

    15. Describe Rutherford’s atom model and explain why it is in agreement with his gold foil experiment.

    16. Which two opposing forces keep electrons stable in the orbit around the nucleus according to Rutherford’s atom model?

    17. What are the two basic problems with Rutherford’s atom model?

    18. What is blackbody radiation?

    19. What assumption did Max Planck make to explain the spectra of blackbody radiation?

    20. Objects first start to glow red, then, orange, and finally white with increasing temperature. Explain why.

    21. What is meant by the “Balmer series”, the “Paschen series” and the “Lyman series”?

    22. Explain why the atomic absorption and emission spectra inspired the Bohr atom model?

    23. What is the meaning of an angular momentum in physics?

    24. Name the four postulates of Niels Bohr that lead to his atom model.

    25. Mathematically derive the terms for the allowed radii and the allowed energies for the electron in an H atom according to Bohr.

    26. Explain why the results of the above calculations explain the atomic spectra of the H atom.

    27. What are the two major problems of the Bohr atom model?

    Section 2

    1. What is the photoelectric effect?

    2. Explain how Einstein verified Planck’s law by investigating the photoelectric effect.

    3. Explain why the wave-particle dualism can explain the photoelectric effect.

    4. What is the name of the particle associated with electromagnetic radiation?

    5. Derive the formula for the wave-particle dualism of electromagnetic radiation.

    6. Give a definition for standing matter waves.

    7. Explain why standing matter waves are quantized.

    8. Derive the Schroedinger equation for the electron in the one-dimensional box.

    9. What are the boundary conditions for the wavefunctions describing the electron in a one-dimensional box.

    10. Derive the wavefunction for the electron in the one-dimensional box.

    11. Explain qualitatively what are the major similarities and differences for an electron in a one-dimensional box compared to an electron in a hydrogen atom.

    12. What are the quantum numbers in the solution of the Schroedinger equation for the hydrogen atom?

    13. The radial probability function is the product of the formula for the surface of a sphere multiplied with the square of the radial function. Explain why this product gives the probability to find the electron at a certain distance (radius) from the nucleus.

    14. At which radius r has the radial probability function of the 1s orbital its maximum?

    15. What is a spherical node in an orbital?

    16. What is an angular node in an orbital?

    17. What types of angular nodes do we know?

    18. Can an s orbitals have angular nodes?

    19. Can p and d orbitals have spherical nodes?

    20. Name an orbital that has a conical node.

    21. What are the formulas for the number of radial, angular, and total number of nodes in an atom?

    22. On which quantum number do the orbital energies in the H atom depend on according to the wavemechanical model of the H atom?

    23. The energy of an electron in the ground state of the hydrogen is -13.6 eV. Explain why this energy is negative.

    24. What are the energies of the electron in the hydrogen atom when the electron is in a 2p and 4f orbital respectively?

    25. Explain the concept of shielding in multi-electron atoms.

    26. Explain why the energy of a 2s orbital in Li is smaller than that of a 2p orbital.

    27. What are the Slater rules for s,p,d, and f electrons respectively?

    28. What is special about the electron configurations of Cr and Cu?

    29. Explain the concept of the spin-pairing energy.

    30. What does Hund’s rule state?

    Section 3

    1. Write down the periodic table of the elements for the elements with the atomic numbers 1 to 86. Include element symbols only.

    2. Listen to Tom Lehrer’s “The Elements” song. Relax.

    3. Which are the three periodic trends for the atomic radii of the elements of the periodic table? Explain these trends.

    4. What is the definition of the ionization energy, the electron affinity, and the electronegativity?

    5. Which are the three periodic trends for the first ionization energies of the elements of the periodic table? Explain these trends INCLUDING their exceptions.

    6. The electron affinities of the group 2, 12, and 18 elements as well as the electron affinity of N are negative. Explain.

    7. Alkali metals have a relatively high electron affinity. Explain.

    8. Explain how Pauling derived his electronegativity scale.

    9. What the periodic trends for the electronegativity of the elements of the periodic table?

    10. Explain why CsAu is an ionic crystal.

    11. Explain why electronegativity differences are related to the dissociation energy differences of homonuclear and heteronuclear bonds.

    12. Explain the concepts of the Allred-Rochow, Mulliken, and Allen electronegativity scale.

    13. Which of the four electronegativity scales we talked about in class cannot make statements about the electronegativity of noble gases like Ne or He. Why?

    14. We combine two elements of low electronegativity to form a compound. Which bonding type would you expect for this compound?

    15. If two elements with high electronegativity are combined, which bonding results then?

    16. If two elements of very different electronegativities are combined, what is the bonding in the compound?

    17. Explain the concept of Ketalaar’s triangle.

    18. Can there be any compounds outside Ketelaar’s triangle?


    Dr. Kai Landskron (Lehigh University). If you like this textbook, please consider to make a donation to support the author's research at Lehigh University: Click Here to Donate.


    1.4: Concept Review Questions Chapter 1 is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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