a. Which is the better color, red or blue, to measure the absorption of a red-colored solution ?
b. based on the following hypothetical graph,
what would be the “best” wavelength to use ?
Ch. 6 & 7 atomic structure & periodic trends test [100 points] AP Chem
For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.
Academic Honesty: The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus. I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam. If you violate any of the preceding items or do not sign, your semester grade is a F.
Signature: ___________________
1. Light with a wavelength of 589 nm shone onto a metal caused the emission of electrons, whose kinetic energy is 1.4 * 10-19 J. What is the minimum frequency needed for electron emission in this metal ? [10 points]
2. What is the ___ of the emitted light due to the transition of an electron in the hydrogen atom from n = 4 to n = 1 energy state ? [15 points]
a. energy
b. frequency
c. wavelength
3. What are all possible set of quantum numbers for an electron in the 2p atomic orbital ? Briefly, describe what aspect of an atomic orbital that corresponds to each quantum number. [10 points]
4. Sketch ___ atomic orbital; include the x-, y-, z- axis to show the relationship between these axis and the atomic orbital. [10 points]
a. px
b. dxy
5. sketch the orbital diagram of ___; use the noble gas “shortcut” notation. [10 points]
a. oxygen
b. arsenic
6. What is the relative ____ between fluorine versus sulfur ? Justify / rationalize your response. [20 points]
a. atomic size
b. (first) ionization energy
7. Write the chemical equation describing the first-, second-, and third- ionization energy for calcium. [10 points]
8. Justify / rationalize, for calcium: 2nd ionization energy << 3rd ionization energy. [10 points]
9. old topic: define “isotope” and provide 2 examples of (reasonable / potential) isotopes. [5 points]
- - - - - - - - - -Ch. 6 & 7 atomic structure & periodic trends retest [100 points] AP Chem
1. Light with a wavelength of 765 nm shone onto a metal caused the emission of electrons with a kinetic energy of 1.35 * 10-19 J. What is the range of wavelength (in meters) needed for electron emission in this metal ? [15 points]
2. In certain situations in the photoelectric effect, the intensity of light does have an effect, while in other situations, the intensity of light has no effect – describe both of these situations. [10 points]
3. rationalize / justify the periodic trend in the (first) ionization energy: [15 points]
a. in general, it increases in a row (left to right)
b. in general, it is relatively stable in the d-block.
c. the exception involving phosphorus and sulfur.
4. write the electron configuration of __ (using nobel gas “shortcut”) and identify the valence and kernel electrons. [10 points]
a. lead
b. strontium
5. lab related questions: justify / rationalize your response. [10 points]
a. Which is the better color, red or blue, to measure the absorption of a red-colored solution ?
b. based on the following hypothetical graph,
what would be the “best” wavelength to use ?
6. electron spin. [15 points]
a. Define “electron spin”
b. relevance to an electron orbital (with respect to the maximum number of electrons in an orbital)
c. relevance to the magnetic properties of an atom ?
7. Pick any 2 of the following choices: describe ___. Clearly identify your choice; will evaluate 2 lowest-scoring choices if you do all three choices. [10 points]
a. aufbau principle
b. Pauli exclusion principle
c. Hund’s rule
8. old topics [15 points]
a. Describe the results of Rutherford’s experiment and its interpretation regarding the atom.
b. For the reaction, H2 + O2 --> H2 O, the
rate = k [H2 ] [O2 ]1/2
if the rate is 2.5 μM / second, [H2 ] = 2.0 mM and [O2 ] = 5.0 mM, then what is the value and units of the rate constant, k ?