CHY 115, HW
#9
1. Which of the
following frequencies corresponds to light with the longest wavelength?
a) 3.00 ´ 10^{13} s^{–1}
b) 4.12 ´ 10^{5} s^{–1}
c) 8.50 ´ 10^{20} s^{–1}
d) 9.12 ´ 10^{12} s^{–1}
e) 3.20 ´ 10^{9} s^{–1}
2. When a
strontium salt is ignited, it burns with a red flame. The frequency of the
light given off by this flame is greater than
a) yellow
light
b) infrared
light
c) ultraviolet
light
d) radio
waves
e) xrays
3. A line in
the spectrum of atomic mercury has a wavelength of 258 nm. When mercury emits a
photon of light at this wavelength, the frequency of this light is
a) 8.61 ´ 10^{–16} s^{–1}
b) 7.70 ´ 10^{–19 }s^{–1}
c) 1.16 ´ 10^{15 }s^{–1}
d) 77.3 s^{–1}
4. What is the
wavelength of a photon of red light (in nm) whose frequency is 4.64 ´ 10^{14} Hz?
a) 646 nm
b) 1.55 ´ 10^{6} nm
c) 155 nm
d) 464 nm
5. Green light
can have a wavelength of 512 nm. The energy of a photon of this light is
a) 1.02 ´ 10^{–31} J
b) 5.12 ´ 10^{–7} J
c) 3.88 ´ 10^{–19} J
d) 5.86 ´ 10^{14} J
e) 2.58 ´ 10^{18} J
6. Which one of
the following types of radiation has the shortest wavelength, the greatest
energy, and the highest frequency?
a) Ultraviolet
radiation.
b) Infrared
radiation.
c) Visible
red light.
d) Visible
blue light.
e) None,
because short wavelength is associated with low energy and low frequency, not
high energy and high frequency.
7. The four
lines observed in the visible emission spectrum of hydrogen tell us that:
a) The
hydrogen molecules they came from have the formula H_{4}.
b) We could
observe more lines if we had a stronger prism.
c) There are
four electrons in an excited hydrogen atom.
d) Only
certain energies are allowed for the electron in a hydrogen atom.
e) The
spectrum is continuous.
8. In an
investigation of the electronic absorption spectrum of a particular element, it
is found that a photon having l = 500 nm provides just enough
energy to promote an electron from the second quantum level to the third. From
this information, we can deduce
a) the energy
of the n = 2 level
b) the energy
of the n = 3 level
c) the sum of
the energies of n = 2 and n = 3
d) the
difference in energies between n = 2 and n = 3
Use the following to answer questions 9,10. Consider the following portion of the energylevel diagram for hydrogen:

n = 4 

–0.1361 ´ 10^{–18} J 

n = 3 

–0.2420 ´ 10^{–18} J 

n = 2 

–0.5445 ´ 10^{–18} J 

n = 1 

–2.178 ´ 10^{–18} J 
9. For which
of the following transitions does the light emitted have the longest
wavelength?
a) n = 4 to n = 3
b) n = 4 to n = 2
c) n = 4 to n = 1
d) n = 3 to n = 2
e) n = 2 to n = 1
10. In the
hydrogen spectrum, what is the wavelength of light associated with the n
= 4 to n = 1 electron transition?
a) 5.96 ´ 10^{–25} nm
b) 1.46 ´ 10^{3} nm
c) 1.03 ´ 10^{7} cm
d) 2.04 ´ 10^{–18} m
e) 9.73 ´ 10^{–8} m
11.
When a hydrogen electron makes a transition from n = 3 to n
= 1, which of the following statements is true?
I. 
Energy is emitted. 
II. 
Energy is absorbed. 
III. 
The electron loses energy. 
IV. 
The electron gains energy. 
V. 
The electron cannot make this transition. 
a) I,
IV b) I, III c) II, III d) II, IV e) V
12. When an
electron in a 2p orbital of a particular atom makes a transition to the
2s orbital, a photon of approximate wavelength 669.5 nm is emitted. The
energy difference between these 2p and 2s orbitals is a) 2.97 ´ 10^{–28} J
b) 2.97 ´ 10^{–19} J
c) 2.97 ´ 10^{–17} J
d) 1.33 ´ 10^{–31} J
13. In Bohr's atomic
theory, when an electron moves from one energy level to another energy level
more distant from the nucleus:
a) Energy is
emitted.
b) Energy is
absorbed.
c) No change
in energy occurs.
d) Light is emitted
.
14. Which of
the following statements best describes the Heisenberg uncertainty principle?
a) The exact
position of an electron is always uncertain.
b) The
velocity of an electron can only be estimated.
c) It is
impossible to accurately know both the exact location and momentum of an
electron.
d) The
location and momentum of a macroscopic object are not known with certainty.
e) The
location and momentum of a particle can be determined accurately, but not the
identity of the particle.
15. Which of
the following best describes an orbital?
a) space
where electrons are unlikely to be found in an atom
b) space
which may contain electrons, protons, and/or neutrons
c) the space
in an atom where an electron is most likely to be found
d) small,
walled spheres that contain electrons
e) a single
space within an atom that contains all electrons of that atom
16. Which of
the following is not determined by the principal quantum number, n,
of the electron in a hydrogen atom?
a) The energy
of the electron.
b) the
minimum wavelength of the light needed to remove the electron from the atom.
c) The size
of the corresponding atomic orbital(s).
d) The shape
of the corresponding atomic orbital(s).
e) All of the
above are determined by n.
17. If n
= 2, how many orbitals are possible?
a) 3 b) 4 c)
2 d) 8 e) 6
18.
The magnetic quantum number is related to the orientation of the orbital
in space relative to the other orbitals in the atom. True or False?
19. How many
electrons in an atom can have the quantum numbers n = 3, l = 2?
a) 2 b) 5 c) 10 d)
18 e) 6
20. How many
electrons can be described by the quantum numbers n = 2, l = 2, m_{l}
= 1?
a) 0 b) 2 c) 6 d) 10 e) 14
21. What is the
l quantum number for a 4p orbital?
a) 2 b) 1 c) 0 d) 3 e) more than one of the above