1. The energy of a photon of light is __________ proportional to its frequency and __________ proportional to its wavelength.

A. directly, inversely B. indirectly, not C. directly, directly D. inversely, inversely E. inversely, directly

2. What is the frequency of light (s-1) that has a wavelength of 1.23 x 10-6 cm?

A. 2.44 x 1014 B. 3.69 C. 4.10 x 10-17 D. 2.44 x 1016 E. 9.62 x 1012

ν = c / λ *remember to convert wavelength to meters*

ν = 3.00 x 108 m/s / (1.23 x 10-8 m) = 2.44 x 1016

3. The energy of a photon that has a wavelength of 13.2 nm is __________ J.

A. 1.99 x 10-25 B. 9.55 x 10-25 C. 6.62 x 1016 D. 1.51 x 10-17 E. 1.51 x 10-26

E = h c / λ *remember to convert wavelength to meters*

i-34 8

-17-9

(6.63 x 10 J s)(3.00 x 10 m / s)E = = 1.51 x 10

13.2 x 10 m

4. Of the following transitions in the Bohr hydrogen atom, the __________ transition results in the emission of the highest-energy photon.

A. n = 3 → n = 6 B. n = 1 → n = 6 C. n = 6 → n = 1 D. n = 6 → n = 3 E. n = 1 → n = 4

For emission to occur, the electron must move from a higher level to a lower one. The biggest gap results in the highest energy photon.

5. The frequency of electromagnetic radiation required to promote an electron from n=2 to n=4 in a Bohr hydrogen atom is __________ Hz.

A. 6.2 x 1014 B. 4.1 x 1019 C. 5.4 x 10-19 D. 8.2 x 1014 E. 4.1 x 10-19

Calculate E with Rydberg equation, and the calculate freq. with ν = E/h

+ = + =

-18 -19H 2 2 2 2

i f

1 1 1 1E = R 2.18 x 10 J 4.1 x 10 J

n n 2 4

ν = E/h = 4.1 x 10-19 J / 4.1 x 10-19 J / 6.63 x 10-19 Js = 6.2 x 1014 s-1

6. The lines in the emission spectrum of hydrogen result from __________.

A. photons given off when an electron moves from a higher energy state to a lower energy state

B. electrons given off by hydrogen when it burns C. protons given off when hydrogen burns D. electrons given off by hydrogen as it cools E. photons given off when a proton moves from a higher energy state to a lower energy state

7. The de Broglie wavelength of a __________ will have the shortest wavelength when traveling at 30 cm/s.

A. planet B. marble C. hydrogen atom D. uranium atom E. car

Recall that λ = h/mv.

Thus the greater the mass, the shorter the wavelength.

A planet is the most massive item in the list and would thus have the shortest wavelength.

8. There are __________ orbitals in the third shell.

A. 16 B. 4 C. 25 D. 1 E. 9

The 3rd shell contains 1 s-orbital, 3 p-orbitals and 5 d-orbitals, giving a total of 9 orbitals

9. The __________ subshell contains only one orbital.

A. 6f B. 3d C. 4s D. 5d E. 1p

The s-sublevel has only one orbital (p has 3, d has 5)

10. An electron cannot have the quantum numbers n = _____, l = _____, ml = _____.

A. 3, 2, -2 B. 1, 0, 0 C. 3, 2, 3 D. 3, 2, 1 E. 6, 1, 0

ml cannot be larger than l, (it ranges from –l to +l, in this case: -3 to +3)

11. In a hydrogen atom, an electron in a __________ orbital can absorb a photon, but cannot emit a photon.

A. 1s B. 3p C. 2s D. 3s E. 3f

An atom only emits a photon when an electron moves from a higher energy orbital to a lower energy level. An electron in the 1s is already in the lowest level and thus cannot move lower.

12. Which set of three quantum numbers (n, l, ml) corresponds to a 3d orbital?

A. 2, 1, 0 B. 3, 1, 1 C. 2, 3, 3 D. 3, 2, 2 E. 4, 3, -3

The 3 of 3d indicates the 3rd shell (n=3) The d-subshell is denoted when l = 2.

13. How many p-orbitals are there in a Ne atom?

A. 1 B. 2 C. 6 D. 3 E. 0

Ne: 1s22s22p6

There is only one p-subshell and each p-subshell has 3 orbitals.

14. Each p-orbital can accommodate a maximum of __________ electrons.

A. 6 B. 1 C. 5 D. 2 ALL orbitals hold a maximum of 2 electrons. E. 3

15. Each p-subshell can accommodate a maximum of __________ electrons.

A. 2 B. 5 C. 10 The p-subshell has 3 p-orbitals, each of which holds a maximum of D. 6 2 electrons, giving a maximum of 6 electrons per p-subshell. E. 3

16. In which orbital does an electron in a phosphorus atom experience the greatest effective nuclear charge?

A. 1s Electrons in the 1st shell have no inner electrons to provide shielding, B. 2s and thus feel the full nuclear charge (+15). C. 2p D. 3s E. 3p

17. In which orbital does an electron in a phosphorus atom experience the greatest shielding?

A. 2p B. 3p Electrons in the most remote shell have the most inner electrons C. 1s providing shielding and consequently experience the greatest D. 2s shielding. E. 1p

18. [Ar]4s23d104p3 is the electron configuration of a(n) _____ atom.

A. P B. Sb C. V D. Sn Add up the electrons: (Ar + 4s + 3d +4p ) 18 + 2 + 10 + 3 = 33 E. As 33 the atomic number of arsenic (As).

19. The ground state electron configuration of Fe is __________.

A. 1s22s22p63s23p63d8 B. 1s22s22p63s23p64s23d6 C. 1s22s22p43s23p44s23d10 D. 1s22s22p63s22d103p4 E. 1s22s22p63s23p64s24p6

20. Which one of the following configurations depicts an excited oxygen atom?

A. 1s22s22p23s2 B. 1s22s22p2 C. 1s22s42p2 D. [He]2s22p4 E. 1s22s22p4

Oxygen has 8 electrons (A, C, D or E). s cannot have 4 electrons so C is impossible. D and E are both ground state configurations, leaving A. In configuration A, two of the p electrons have been raised from the 2p to the 3s subshell.

21. A fluorine atom has _____ unpaired electrons and is _____.

A. no, diamagnetic B. one, paramagnetic C. two, diamagnetic D. one, diamagnetic E. no, paramagnetic

Atoms (and molecules) with unpaired electrons are paramagnetic

22. The ground state electron configuration of an element with the smallest number of valence electrons is __________. A. 1s22s22p63s23p64s1 B. 1s22s22p63s2 C. 1s22s22p13s23p64s23d1 D. 1s22s22p63s23p6 E. 1s22s22p63s23p64s23d104p1

one valence electron (4s1) two valence electrons (3s2) two valence electrons (4s2) eight valence electrons (3s23p6) three valence electrons (4s24p1)

23. In which set of elements would all members be expected to have very similar chemical properties?

A. Na, Mg, K B. O, S, Se Elements within a group have very similar chemical properties. C. Ne, Na, Mg D. N, O, F E. S, Se, Si

24. Atomic radius generally increases as we move __________.

A. up a group and from left to right across a period B. down a group and from left to right across a period C. down a group; the period position has no effect D. down a group and from right to left across a period E. up a group and from right to left across a period

25. Of the following, which gives the correct order for atomic radius for Mg, Na, P, Si and Ar?

A. Ar > Si > P > Na > Mg B. Si > P > Ar > Na > Mg C. Na > Mg > Si > P > Ar see problem 24 above D. Mg > Na > P > Si > Ar E. Ar > P > Si > Mg > Na

26. The electron configuration of the atom that is expected to form a stable -2 ion is _____.

A. [Kr] 5s1 B. [Ne] 3s23p5 C. [Ar] 4s23d104p4 This is a chalcogen, which forms –2 anions. Also, two more electrons D. [Ne] 3s23p6 would result in a noble gas configuration. E. [Ar] 4s1

27. The electron configuration of the atom that is expected to have the lowest first ionization energy is __________.

A. [Kr] 5s1 B. [Ne] 3s23p5 C. [Ar] 4s23d104p4 D. [Ne] 3s23p6 E. [Ar] 4s1

Electrons in ns1 orbitals (A & E) experience the lowest Zeff. However, the 5s orbital is further from the nucleus than the 4s, so A has the lowest 1st ionization energy.

28. Of the choices below, which gives the order for first ionization energies?

A. S > Si > Cl > Al > Ar B. Cl > S > Al > Ar > Si C. Al > Si > S > Cl > Ar D. Cl > S > Al > Si > Ar E. Ar > Cl > S > Si > Al

Zeff decreases going across a period from right to left, and 1st ionization energies should follow this same trend.

29. Which of the following has the largest second ionization energy?

A. P B. Al C. Na D. Mg E. Si

Na has a low 1st ionization, giving Na+. However, Na+ has a noble gas configuration, so removing the second electron is very high energy.

30. Which isoelectronic series is correctly arranged in order of increasing radius?

A. Ca2+ < Ar < K+ < Cl- B. Cl- < Ar < K+ < Ca2+ C. Ca2+ < K+ < Cl- < Ar D. Ca2+ < K+ < Ar < Cl- E. K+ < Ca2+ < Ar < Cl-

All have 10 inner shell electrons to provide shielding. Size will inversely mirror Zeff. Zeff(Ca2+) = 10, Zeff(K

+) = 9, Zeff(Ar) = 8, Zeff(Cl-) = 7

31. Of the elements below, __________ has the greatest (most negative) electron affinity.

A. chlorine Electron affinity increases (becomes more negative) as one goes B. sodium across a period (from left to right) and up a group. C. hydrogen D. neon E. sulfur

32. Na reacts with element X to form an ionic compound with the formula Na3X. Ca will react with X to form _____.

A. CaX B. Ca2X3 C. Ca3X2 D. CaX2 E. Ca3X

Since sodium forms Na+, X must be X3-. Given that calcium forms Ca2+, the resulting formula is Ca3X2.