100 AP Chemistry

EP

Practice Exercises

Multiple-ChoiceFor the first three problems below, oneor more of the following responses willapply; each response may be used morethan once or not at all in thesequestions.

I. Rydberg equationII. Heisenberg uncertainty prin-

cipleIII. Hund's ruleIV. Pauli exclusion principleV. Bohr model

1. Our inability to know precisely theposition and momentum of asubatomic particle is summarizedby

(A) I(B) II(C) III(D) IV(E) V

2. In filling the atom with electrons,the rulets) that must be consideredare

(A) I and III(B) II and V(C) III and IV(D) IV(E) III

3. The best tool to use to calculate theionization energy of a hydrogenatom IS

(A) I(B) II(C) III(D) IV(E) V

For the next three problems below, oneor more of the following responses willapply; each response may be used morethan once or not at all in thesequestions.

I. nII. 5

III. m!

IV. m,V.I4. Which of these symbols represents

an orbital?

(A) I and II(B) II and V(C) I, II, and V(D) III and IV(E) V

5. This designation for an electron incalcium can occur only if calcium isin an excited state.

(A) I and II(B) II and V(C) I, II, and III(D) III and IV(E) V

6. Which of these will tell you theshape of any orbital that anelectron may occupy?

(A) I(B) II(C) III(D) IV(E) V

7. Which of the following types ofelectromagnetic radiation has thehighest energy?

(A) visible(B) ultraviolet(C) microwave(D) infrared(E) X rays

8. What is the wavelength oflight that has a frequency of4.00 X 1014 S-I? (The speed of lightis 3.00 X 108 m S-I.)

(A) 7.5 nm(B) 1333 nm(C) 750. nm(D) 1.33 cm-I

(E) 1.2 X 1023 m

9. Which of the following elementshas the greatest number of pelectrons?

(A) C(B) Si(C) Fe(D) Cl(E) As

10. An electron with the four quantumnumbers 3, 2, -1, -1 may be anelectron in an unfilled sublevel of

(A) Ca(B) Fe(C) AI(D) Ar(E) Ag

11. For a d orbital:

(A) the value of n must be 2(B) the value of m, must be +1(C) the value of e must be 3(D) the value of me' must be 3(E) the value of e must be 2

Structure of the Atom 101

12. The numbers of electrons, protons,and neutrons, respectively, in the31p.Isotope are

(A) 15,31, 15(B) 15, 15, 31(C) 31, 15, 16(D) 15, 15, 16(E) 31, 31, 16

13. Which element has an electronicconfiguration that does NOTfollow the Aufbau principle?

(A) Fe(B) Mg(C) AI(D) Ag(E) Ni

14. Which electronic configurationcorresponds to that of a noble gas?

(A) Is2 2/ 2l 3s2 3l 4s1

(B) 1/ 2s2 2l 3s2 3/(C) ls2 2s2 2l 3s2 3l(D) Is2 2s2 2l 3s1

(E) Is 2s 2p 3s 3p

15. Which electronic transition requiresthe addition of the most energy?

(A) n = 1 to n = 3(B) n = 5 tox = 2(C) n = 2 to n = 3(D) n = 4 to n = 1(E) n = 5 to n = 1

16. Which of the following has onlyfive valence electrons?

(A) Rb(B) C(C) Si(D) p(E) B

102 AP Chemistry

17. Which was used to determine thecharge of the electron?

(A) the gold foil experiment(B) deflection of cathode rays by

electric and magnetic fields(C) the oil drop experiment(D) electrolysis(E) the mass spectrometer

18. Which of the following principles isNOT part of Dalton's atomictheory?

(A) Atoms are the smallest,indivisible particles in nature.

(B) Chemical reactions are simplerearrangements of atoms.

(C) Atoms follow the law ofmultiple proportions.

(D) Each atom of an element isidentical to every other atomof that element.

(E) All matter is composed ofatoms.

19. Which of the following atoms hasthe most unpaired electrons?

(A) Mg(~) Ti(C) Al(D) Cu(E) Cr

20. Which quantum number describesthe shape of an orbital? .

(A) n(B) e(C) me(D) m,(E) s

21. You have just discovered a new,fundamental particle of nature.When measuring its mass, youobtain the following data for fivesamples:

4.72 X 10-34 gram9.44 X 10-34 gram1.18 X 10-33 gram1.65 X 10-33 gram7.08 X 10-34 gram

Millikan found the mass of anelectron by finding the commonfactor in a mass of data. What isthe common factor in the datapresented?

(A) 4.72 X 10-34 g(B) 1.18 X 10-34 g(C) 9.44 X 10-34 g(D) 2.36 X 10-34 g(E) 9.91 X 10-34 g

I CHALLENGE I22. Which of the following is FALSE?

(A) The 4d orbitals are in thefourth period of the periodictable.

(B) The 7s orbitals are in theseventh period of the periodictable.

(C) The 4/ orbitals are in the sixthperiod of the periodic table.

(D) The 6s orbitals are spherical inshape.

(E) The 5p orbitals are dumbbell-shaped.

23. The [sublevel may contain amaximum of

(A) 2 electrons(B) 14 electrons(C) 6 electrons(D) 10 ~lectrons(E) 8 electrons

24. The valence electrons are

(A) all electrons in an atombeyond the preceding noblegas

(B) all outermost electrons in asublevel

(C) s and any p electrons in thehighest energy level or shell

(D) electrons in the last unfilledsublevel

(E) any electrons that can ionize

Structure of the Atom 103

25. Which equation best expressestheenergy of a photon?

(A) E= ±mv2

(B) E= mc2

(C) E= IR(D) E= hv(E) E= EO - RTln K

I CHALLENGE I26. Bohr's equation for the energy of

an electron in its orbit can be used

(A) to calculate the energy releasedas an electron drops from ahigh orbit to a lower one

(B) to calculate the ionizationenergy of hydrogen

(C) to determine the energyneeded to promote an electronto a higher energy.level

(D) to understand the spectra ofthe hydrogen atom

(E) for all of the above purposes

ANSWER KEY1. B 7. E 13. D 19. E 25. D2. C 8. C 14. C 20. B 26. E3. A 9. E 15. A 21. D4. B 10. B 16. D 22. A5. E 11. E 17. C 23. B6. C 12. D 18. C 24. C

See Appendix 1 for explanations of answers.