# Chapter 7 Problem Set 4

```WOLPA/AP CHEMISTRY
CHAPTER SEVEN: ATOMIC STRUCTURE
Problem Set Four
"potentially useful information."
N = 6.022 x 1023 particles per mole
h = 6.626 x 10-34 J-s
c = 2.998 x 108 m/s
RH = 1.097 x 10-2 nm-1 = 2.18 x 10-18 J
E = - 1312 Kj/mol/n2
1. Which of the following postulates of Dalton's atomic theory is still valid today?
(I) Matter consists of particles called atoms.
(II) Atoms are indestructible and indivisible.
(III) All atoms of an element are identical.
(IV) Atoms of different elements differ in mass.
(V) When the atoms of different elements combine to form compounds they
combine in simple whole number ratios.
(a) All of these statements are still valid today.
(b) I and II are still valid, but not III, IV and V.
(c) I, II and III are still valid, but not IV and V.
(d) I, IV and V are still valid, but not II and III.
(e) II and III are still valid, but not I, IV and V.
2. Which describes the difference between the
12C, 13C
and 14C isotopes of carbon?
(a) They have the same number of protons but different numbers of electrons.
(b) They have the same number of neutrons but different numbers of electrons.
(c) They have the same number of electrons but different numbers of protons.
(d) They have the same number of protons but different numbers of neutrons.
(e) They have the same number of protons, electrons, and neutrons but different atomic
masses.
3. What would you describe as the key result of the Rutherford experiment, in which a
metal target was bombarded with -particles?
(a) The -particles were able to pass through the target.
(b) The particles were found to knock electrons out of the target.
(c) Some of the -particles were deflected through large angles.
(d) Flashes of light were emitted when the -particles hit the ZnS screen after they
passed through the target.
(e) The experiment showed the need for better -particle detectors.
4. What do we mean when we say that "The energy of the electron in an atom is
quantized?"
(a) The electron has a very small energy.
(b) The energy of the electron is proportional to the mass of the nucleus.
(c) When an electron changes it energy, it emits a quantum of light.
(d) The energy of the electron can have certain fixed energies and not others.
(e) The electron must be a wave.
5. Which of the following statements is inconsistent with modern quantum mechanics?
(a) The hydrogen atom emits light at only a limited number of discrete frequencies.
(b) In the ground state of the hydrogen atom the electron is constrained to a circular
orbit.
(c) The energy of the hydrogen atom is quantized.
(d) No two electrons in an atom can have the same set of four quantum numbers. (e)
The spin quantum number has a half-integral value.
6. What is the wavelength in centimeters of light that has a frequency of 2.33 x 1015 s-1?
(a) 6.99 x 1025 cm
(b) 7.77 x 104 cm
(c) 1290 cm
(d) 1.29 x 10-5 cm
(e) none of the above
7. A helium-neon laser emits light with a wavelength of 6328 . What is the energy of a
6328 photon in joules?
(a) 2.179 x 10-19 J
(b) 3.139 x 10-19 J
(c) 5.448 x 10-19 J
(d) 6.328 x 10-19 J
(e) 2.179 x 10-18 J
8. If green light has a frequency of 5.0 x 1014 s-1 what is the wavelength (in meters) of
this light?
(a) 6.7 x 10-24
(b) 2.0 x 10-15
(c) 6.0 x 10-7
(d) 3.0 x 108
(e) none of the above
9. If x-rays have a shorter wavelength than ultraviolet-rays, which of the following
statements is true?
(a) x-rays have smaller frequencies than UV-rays.
(b) x-rays travel faster than UV-rays.
(c) x-rays have more energy than UV-rays.
(d) x-rays have a larger amplitude than UV-rays.
(e) none of the above statements are true.
10. Which of the following could convert a nonionizing form of electromagnetic radiation
into a form of ionizing radiation?
(a) decreasing the wavelength of the radiation.
(b) decreasing the energy of the radiation.
(c) decreasing the frequency of the radiation.
(d) all of the above are true.
(e) none of the above are true.
11. There is a fundamental difference between the long wavelength IR radiation given
off by the toy ovens sold at Toys ‘R Us and the shorter wavelength UV radiation emitted
by the tanning booths at your local strip mall. Which of the following statements is true?
(e) None of the above statements are true.
12. A cheap spectrophotometer can be made using a light-emitting diode as the source
of the light. Assume that you build one of these spectrometers using an LED that gives
off green light with a wavelength of 520 nm. What is the energy of a photon of this green
light?
(a) 1.15 x 10-34 J
(b) 1.03 x 10-22 J
(c) 3.82 x 10-21 J
(d) 3.82 x 10-19 J
(e) none of the above
13. What is the maximum number of unpaired electrons that can be accommodated in a
5d subshell?
(a) 3
(b) 5
(c) 6
(d) 7
(e) 10
14. When Schrödinger’s wave mechanics model is applied to an isolated atom in the
gas phase, the energy of an electron in an orbital on the atom is determined by which
pair of quantum numbers?
(a) n and l (b) n and m (c) n and s (d) l and m (e) m and s
15. Which of the following is an incorrect order of increasing energy of the atomic
orbitals?
(a) 3s < 4s < 5s
(b) 5s < 5p < 5d
(c) 5s < 4d < 5p
(d) 5p < 6s < 4f
(e) None of these are incorrect
16. Which set of orbitals is arranged in increasing order of energy?
(a) 3d < 4s < 4p < 5s < 4d
(b) 3d < 4s < 4p < 4d < 5s
(c) 4s < 3d < 4p < 5s < 4d
(d) 4s < 3d < 4p < 4d < 5s
(e) 3d < 4s < 4p < 4d < 5s
17. In what group of the periodic table would an element with the following electron
configuration belong?
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1
(a) Group IA
(b) Group IlIA
(c) Group VA
(d) Group VIIA
(e) none of the above
18. A single atom of element 109 has been synthesized. Predict the electronic
configuration of this element. Which of the following elements would 109 most
resemble?
(a) Ta
(b) Re
(c) Ir
(d) Au
(e) Tl
19. A single atom of element 114 was recently synthesized. Predict the electronic
configuration of this element. Which of the following elements would 114 most
resemble?
(a) Au
(b) Hg
(c) Tl
(d) Pb
(e) Po
20. Which element has the largest number of electrons for which the angular quantum
number is equal to 1?
(a) He
(b) F
(c) S
(d) As
(e) Zn
21. A possible set of quantum numbers for the last electron added to form a gallium
atom (Z = 31) in its ground state is:
(a) 3, 1, 0, -½
(b) 3, 2, 1, ½
(c) 4, 0, 0, ½
(d) 4, 1, 1, ½
(e) 4, 2, 2, ½
22. An element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2 4d10
5p3 would belong in which group or family of the periodic table?
(a) Group IA
(b) Group IIIA
(c) Group IVA
(d) Group VA
(e) Group VIIA
23. What is the ground state electronic configuration of a fluorine atom?
(a) 1s2 2s2 2p5
(b) 1s2 2s2 2p6
(c) 1s2 2s2 2p7
(d) 1s2 2s2 2p6 3s1
(e) none of the above
24. What is the value of x in the following electron configuration for silicon?
1s2 2s2 2p6 3s2 3px
(a) 1
(b) 2
(c) 3
(d) 4
(e) 6
25. What is the correct electron configuration for the Ti atom?
(a) 1s2 2s2 2p6 3s2 3p6 3d4
(b) [Ar] 4s2 4d2
(c) [Ar] 4d4
(d) 1s2 2s2 2p6 3s2 3d2
(e) [Ar] 4s2 3d2
26. Which of the following would have the electron configuration:
1s2 2s2 2p6 3s2 3p6 3d4
(a) Ca2+
(b) Cr2+
(c) Fe2+
(d) Ti2+
(e) none of these
27. What is the correct electron configuration for the P3+ ion?
(a) [Ne]
(b) [Ne] 3s2
(c) [Ne] 3s2 3p3
(d) [Ne] 3s2 3p6
28. What is the electron configuration for the bromide ion, Br-?
(a) [Ar] 4s2 4p5
(b) [Ar] 4s2 3d10 4p7
(c) [Ar] 4s2 3d10 4p5
(d) [Ar] 4s2 3d10 4p6
(e) [Ar] 4s2 3d10 3p6
29. Which of the following describes the electron configuration for the Sn 2+ ion?
(a) [Kr] 4d10
(b) [Kr] 5s2
(c) [Kr] 5s2 5p2
(d) [Kr] 5s2 4d10
(e) [Kr] 5s2 4d10 5p2
30. If the X2- ion has no unpaired electrons, in what Group does element X belong?
(a) IA
(b) IIA
(c) IVA
(d) VIA
(e) VIIA
31. Which neutral atom has the most unpaired electrons?
(a) Na
(b) Al
(c) Si
(d) P
(e) S
32. Which atom contains the largest number of unpaired electrons?
(a) B
(b) N
(c) F
(d) Ti
(e) Cu
33. Which atom or ion has the largest number of unpaired electrons?
(a) Li+
(b) B
(c) C4-
(d) N
(e) O2-
34. A possible set of quantum numbers for the last electron added to form an As3+ ion
is:
(a) 3, 1, -1, ½
(d) 4, 1, -1, ½
(b) 4, 0, 0, -½
(e) 5, 0, 0, ½
(c) 3, 2, 0, ½
35. The outermost or highest energy electron in element 105 could be characterized by
which of the following sets of n, l, m and s quantum numbers?
(a) 7, 3, -3, -½
(c) 6, 2, 0, ½
(b) 6, 3, -1, -½
(d) 5, 3, -1, -½
36. Which of the following describes a possible set of quantum numbers for the last
electron added to form an aluminum atom when atomic orbitals are filled?
(a) 1, 0, 0, +½
(d) 3, 0, 0, +½
(b) 2, 0, 0, +½
(e) 3, 1, 1, +½
(c) 2, l, 1, +½
37. Which of the following sets of n, l, m and s quantum numbers could describe the
electron removed from a neutral Al atom when the first ionization energy of aluminum is
measured?
(a) 1, 0, 0, +½
(d) 3, 0, 0, +½
(b) 2, 0, 0, +½
(e) 3, 1, l, +½
(c) 2, 1, 1, +½
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