Download Review: Chapter 11 Modern Atomic Theory (p 1 of 2) Review

Review: Chapter 11 Modern Atomic Theory (p 1 of 2)
1.
The concept of the nuclear atom left unanswered
questions about
a. why the nucleus is so dense
b. why the negative electrons do not collapse
into the positive nucleus
c. what isotopes are
d. the mass of the nucleus
2.
The relationship between the wavelength and
frequency of radiation is expressed by the
equation:
a. λν = c
b. λ = 1/ν
c. ν = cλ
d. ν = 1/c + λ
3.
The concept of photons emphasizes the particlelike nature of light rather than its wave-like
nature. A photon of infrared light has more energy
in it than a photon of
a. visible light
b. ultraviolet light
c. x-rays
d. microwave radiation
7.
In the wave mechanical model of the atom,
electron orbitals are probability density diagrams
of where the electron is likely to be found. These
maps of where the electron is most likely to be
were developed
a. from atomic emission spectra
b. by Niels Bohr
c. by experiments with a cathode ray tube
d. from mathematical analyses by
Schrödinger
8.
At the third principal energy level of an atom, the
number of orbitals equals
a.
3
b.
6
c.
9
d.
12
9.
The number of electrons that can be
accommodated in the n = 2 level is:
a.
2
b.
4
c.
6
d.
8
4.
When the electrons in atoms receive energy from a
source, they go into an excited state but quickly
return back to ground state by
a. nuclear fusion
b. emitting a photon of light
c. emitting a proton
d. absorbing heat
10. Write out the electron configuration for an atom
of phosphorus and indicate the number of unpaired
electrons
a. [Ne]3s23p3 ; 3 unpaired electrons
b. [Ne]2s22p63s23p3 ; 3 unpaired electrons
c. [Ne]3s23p3 ; 5 unpaired electrons
d. [Ne]3p5 ; 5 unpaired electrons
5.
The concept that electrons in an atom can only
occupy specific energy levels is equivalent to saying
that the energy levels are
a. varied
b. quantized
c. superimposed
d. continuous
11. The number of valence electrons in an atom of Cl
is:
a. 7
b. 5
c. 3
d. 1
6.
The Bohr model of the hydrogen atom explained
the emission spectrum of the hydrogen atom with
the concept of
a. quantized energy levels
b. quantized electron orbits
c. transitions of electrons from higher to
lower energy levels
d. all of the above
12. The Lanthanides correspond to filling up the
____set of orbitals.
a.
3d
b.
3f
c.
4f
d.
5f
13. Which of the following atoms is likely to have the
largest atomic radius?
a. Na
b. Al
c. Cl
d. K
e.
Review: Chapter 11 Modern Atomic Theory
(p 2 of 2)
14. Which element would be likely to have the lowest ionization energy?
a.
Na
b.
Al
c.
Cl
d.
Cs
ANSWERS
1. Choice B properly explains that the nuclear atom did not explain the stable position of electrons relative to the positive nucleus.
2. Choice A provides the correct relationship: Wavelength (λ) x frequency (ν) = the speed of light in a vacuum (c)
3. D. X-rays, UV light, and visible radiation are all more energetic than infrared.
4. B correctly describes a common mode of relaxation of excited state atoms.
5. B reflects the concept that there are specific allowable energy levels in which electrons can exist.
6. D reflects the quantized nature of the electron energy levels and the production of photons of specific energies that correspond to
transitions between quantized levels.
7. D presents the idea that electron orbitals are mathematical descriptions of electron probability densities, derived from solutions to the
Schrödinger equation.
8. Choice C correctly identifies the sum of the orbitals at that level: one 3s orbital + three 3p orbitals + five 3d orbitals = nine orbitals.
9. D correctly predicts that 8 electrons can fit in the n = 2 level. Two electrons fill the 2s orbital and 6 electrons fill the set of three 2p
orbitals.
10. A is correct. Each of the three 3p orbitals has one unpaired electron in it. The electrons in the 3s orbital are paired.
11. A is correct. Cl has 2 valence electrons in the 3s orbital and 5 in the 3p subset.
12. C correctly associates the 14 elements that make up the lanthanides with 14 available slots for electrons in the set of seven 4f orbitals.
13. D. Atomic radius decreases as one proceeds across the third period, but increases from top to bottom.
14. Choice D should be selected. Ionization energy increases from left to right, but decreases as from top to bottom.