Midterm 1

Only available on StudyMode
  • Topic: Quantum mechanics, Atomic orbital, Electron configuration
  • Pages : 22 (8222 words )
  • Download(s) : 63
  • Published : November 17, 2012
Open Document
Text Preview
Chemistry 110 Midterm 1 October 11, 2005 1. What are the possible values for the orbital angular momentum quantum number l given the following values for the other three quantum numbers: n = 4, l = ?, ml = 0, ms = +1/2 A. B. C. D. E. 0 1, 2, 3, or 4 3 0, 1, 2, or 3 none of these answers

2. If the wavelength of an electron is equal to the radius of the n=2 orbit in He+, what must the velocity of the electron be? A. B. C. D. E. 6.88 x 106 m/s 1.38 x 107 m/s 3.44 x 106 m/s 5.47 x 105 m/s The velocity cannot have an exact value

3. The element seaborgium (Sg) has Z=106. What would you predict the electron configuration to of Sg2+ to be? A. B. C. D. E. The same configuration as rutherfordium (Rh) Z=104 [Rn] 6d4 [Rn] 5f14 6d4 [Rn] 5f14 6d2 7s2 [Rn] 5f12 6d4 7s2

4. Praseodymium (Pr Z=59) is one of the lanthanide (rare earth) elements. Which of the following statements is a TRUE statement about the orbital into which the last electron was filled for the element Pr? A. B. C. D. E. The number of radial nodes is greater than the number of angular nodes The orbital is a 5f orbital The orbital contains valence electrons The orbital is one member of a set of seven degenerate orbitals none of the other four statements is true

5. Davisson and Germer (as well as G. P. Thompson) conducted a famous and important experiment. Which of the following statements is TRUE concerning their experiment? A. B. C. D. E. They observed diffraction patterns from photons confirming that light had wave properties They observed diffraction patterns of electrons confirming that matter had wave properties Their experiment contradicted DeBroglie’s equation They observed standing wave patterns from electrons confirming the existence of orbitals None of the other four statements is true

Page 1, v1

Chemistry 110 Midterm 1 October 11, 2005 6. A two-photon absorption transition is observed using a laser that emits light having a wavelength of 500 nm? Which of the following statements is/are TRUE about this electronic transition? A. B. C. D. E. The single photon transition would be caused by UV light with a wavelength of 1000 nm The single photon transition would be caused by IR light with a wavelength of 1000 nm The single photon transition would be caused by UV light with a wavelength of 250 nm The single photon transition would be caused by IR light with a wavelength of 250 nm None of the other four statements is true

7. Which of the following statements is/are TRUE ? A. The wavefunction, ψ, is a solution to the Schrodinger equation B. The square of the wavefunction, ψ 2, is the total probability of finding the electron in a spherical shell at distance r from the nucleus C. Orbitals with the same n cannot overlap in space D. For the same orbital type (i.e. same l quantum number), orbitals with the higher n value will have a more negative energy E. two of the other four statements are true 8. Which is not a valid set of quantum numbers for an electron? A. B. C. D. E. n = 6, l = 2, ml = 0, ms = 1/2 n = 3, l = 2, ml = -2, ms = 1/2 n = 7, l = 0, ml = 0, ms = 1/2 n = 17, l = 16, ml = 16, ms = -1/2 n = 4, l = -2, ml = 2, ms = -1/2

9. Which statement(s) is (are) FALSE in comparing the electronic transition from ni = 5 to nf =2 in H with that of electronic transition from ni = 2 to nf =5 in Be3+ A. The photon involved in the H transition lies in the visible spectrum while that involved in the Be3+ transition lies in the UV region of the spectrum. B. A photon of the same frequency is involved in both transitions, but is emitted the H electronic transition and absorbed in the Be3+ electronic transition. C. The wavelength of the photon emitted by H is 16 times the wavelength of the photon absorbed by Be3+ D. The transition in H is a Balmer emission series line E. two of the other four statements are FALSE

Page 2, v1

Chemistry 110 Midterm 1 October 11, 2005 10. Assume that we conduct a Stern Gerlach type experiment by passing a beam of cobalt (Co)...
tracking img