home   /   exams   /   exam 2

2 Ex exam 2    10/10

We now have an official Exam Procedure page. Check it out and know what to expect on Tuesday.

Coverage for Exam 2: Exam 2 covers all the material that was covered on LE's 09-14 and HW03 and HW04. Most of the exam is over Chapter 2 (Atomic Theory) from the gchem site. There are no stoichiometry problems. This exam is really all about electromagnetic radiation and atomic theory. Remember that the extra practice assignments (4-6) on canvas are a good way to prep as well.

Length / Time for Exam 2: You should expect 20 multiple choice questions. The questions will have a range of point values from 4 points to 6 points. Remember that the point values are included with all questions. The exam is given during class time (9:30-10:45, 11-12:15) which is 75 minutes total which includes the handout time.

Nomenclature is IN As promised on the exam 1 prep page, nomenclature will be on exam 2 (and exam 3 for that matter). So know your polyatomic ions, formulas, charges, etc. Know what is on this gchem data page for polyatomic ions (you don't have to know the "older" names for metal cations)./p>

Main Equations/Formulas for Exam 2

electromagnetic radiation: \[c = \lambda \cdot \nu \]

single photon energy: \[E = h \cdot \nu \]

work function: \[E_{\rm k} = {1\over 2} m v^2 = h\nu - \Phi \]

Rydberg formula: \[\Delta E = {\cal R}\left({1\over n_i^2} -{1\over n_f^2}\right) \]

H Energy Levels: \[E_n = -{\cal R}\left({1\over n^2}\right) \]

The Rydberg constant

(\({\cal R}\)) is clearly labeled and given on the Exam Periodic Table Handout which you will recieve with your exam. Actually, three values are given - use your favorite!

\({\cal R}= 2.18\times 10^{-18} \; \;{\rm J}\)
\({\cal R}= 1.097\times 10^{7} \; \;{\rm m^{-1}}\)
\({\cal R}= 3.29\times 10^{15} \; \;{\rm s^{-1}}\)

EM radiation

light : it's a wave! it's a particle!

Emission vs Absorption

emission: the electron drops down to lower level

absorption: the electron jumps up to higher level

Quantum Concepts

total nodes (nodal surfaces actually) in a given orbital    \(= (n-1)\)

angular nodes (cones and planes)    \(= \ell\)

spherical or radial nodes (spheres)    \(= n - \ell - 1\)

Electron Configurations

use the periodic table to follow the Aufbau order

when making cations from transition metals - remove the \(s\) electrons first

Learning Outcomes for Atomic Theory

Students will be able to...

  1. Perform quantitative calculations based on the relationship between wavelength, energy, and the speed of light.
  2. Identify and rank the different types of radiation which comprise the electromagnetic spectrum.
  3. Explain why classical mechanics doesn't describe electromagnetic radiation.
  4. Describe the photoelectric effect and relate the energy and/or intensity of the photons to the work function and kinetic energy of the ejected electrons.
  5. Explain the origin of atomic and emission spectra and relate these spectra to discrete energy levels.
  6. Apply the Rydberg formula to predict the energy of transitions between fixed energy levels in the hydrogen atom.
  7. Explain that quantum mechanics is a mathematical model, the solutions of which yield wave functions and energies.
  8. List the possible combinations of quantum numbers that are allowed.
  9. State the atomic orbital names based on quantum numbers.
  10. Explain that a wave function can be used to calculate a radial distribution function that describes the probability of an electron as a function of distance away from the nucleus
  11. Distinguish between one-electron systems and multi-electron systems.
  12. Apply the Aufbau principle to determine the configuration for any atom or ion.
  13. Relate the electronic configuration of an element to its position on the periodic table.
  14. Recognize that there are exceptions to the Aufbau principle and predict where on the periodic table these are likely to occur.
  15. Apply Hund's Rule and the Pauli Exclusion Principle to determine electron configuration using an orbital diagram (electrons in individual orbitals with spins).
  16. Fill an electron atomic orbital diagram and determine whether the element is paramagnetic or diamagnetic.
  17. Apply the shell model of multi-electron atoms to describe the concept of core vs. valence electrons.
  18. Describe the organization of the periodic table and the characteristics of elements in different regions of the table.
  19. Describe the concept of electronic shielding and effective nuclear charge (Zeff) and their relationship to trends in ionization energy, atomic radii, and ionic radii.