MR. SURRETTE
VAN NUYS HIGH SCHOOL
CHAPTER 19: THE ATOM AND THE NUCLEUS
WORKSHEET SOLUTIONS
1. The restriction that no more than one electron may occupy a given quantum state was first stated by:
(A) Bohr
(B) de Broglie
(C) Heisenberg
(D) Pauli
(E) Einstein
1A. (D) Pauli
2. When a cool gas is placed between a glowing wire filament source and a diffraction grating, the
resultant spectrum from the grating is:
(A) line emission
(B) red-shifted
(C) continuous
(D) monochromatic
(E) line absorption
2A. (E) line absorption
3. If the radius of the electron orbit in the n = 1 level of the hydrogen atom is 0.053 nm, what is the
radius for the n = 5 level ?
3A.
(1) rn = n2a0
(2) r5 = 52 (0.053 nm)
(3) r5 = 1.33 x 10-9 m
4. 13.6 eV is needed to ionize a hydrogen atom. From the ground state of an electron in a hydrogen
atom, what wavelength is needed if a photon accomplishes this task?
4A.
(1) E = (13.6 eV)(1.6 x 10-19 J / 1 eV)
(2) E = 2.176 x 10-18 J
(3) E = hf
(4) f = E / h
(5) f = 2.176 x 10-18 J / 6.63 x 10-34 J.s
(6) f = 3.28 x 1014 Hz
(7) v = f 
(8)  = c / f
(9)  = (3.00 x 108 m/s) / (3.28 x 1014 Hz)
(10)  = 9.14 x 10-7 m
(11)  = 914 nm
1|Page
CHEMISTRY
MR. SURRETTE
VAN NUYS HIGH SCHOOL
5. When a glowing wire filament source is placed behind a diffraction grating, the resultant spectrum
from the grating is:
(A) line emission
(B) line absorption
(C) continuous
(D) monochromatic
(E) blue-shifted
5A. (A) line emission
6. A radioactive material initially has an activity of 1200 counts/sec. If six hours later it has an activity
of 300 counts/sec, what is its half life?
6A.
(1) 1200  600  300
(2) 2 half-lives have gone by, since each arrow represents one half-life.
(3) Let x = one half-life.
(4) Since the total time is 6 hours: 2x = 6 hours
(5) x = 3 hours
7. 88Ra-226 decays to 86Rn-222 by emitting what type of particle:
(A) beta
(B) proton
(C) gamma
(D) positron
(E) alpha
7A.
A= number of nucleons
Z = number of protons
(1) Parent particle:
A = 226 Z = 88
(2) Daughter particle: A = 222 Z = 86
(3) A = 4 Z = 2
(4) (E) alpha particle
8. How does the daughter nucleus differ from the parent in the beta emission process?
(A) atomic mass increases by one
(B) atomic number increases by two
(C) atomic number increases by one
(D) atomic mass decreases by two
(E) atomic charge increases by two
8A. (C) atomic number increases by one
2|Page
CHEMISTRY
MR. SURRETTE
VAN NUYS HIGH SCHOOL
9. What is the Q-value when one hydrogen atom and one neutron combine to form a deuterium atom?
(hydrogen 1.007825 u, neutron 1.009665 u, deuterium 2.014100 u)
9A.
Let mB = “mass before reaction”
Let mA = “mass after reaction”
(1) mB = 1 H + 1 n
(2) mB = 1.007825 u + 1.009665 u
(3) mB = 2.01749 u
(4) mA = 2H
(5) mA = 2.014100 u
(6) m = mB - mA
(7) m = 2.01749 u – 2.014100 u
(8) m = 0.00339 u
(9) E = mc2
(10) E = (m)c2
(11) E = (0.00339 u)(931.5 MeV / 1u)
(12) E = 3.16 MeV
10. If C-12 has 6 neutrons, how many neutrons are in C-14?
10A.
(1) A1 = Z + N1
(2) Z = A1 – N1
(3) Z = 12 – 6
(4) Z = 6 (number of protons in C)
(5) A2 = Z + N2
(6) N2 = A2 – Z
(7) N2 = 14 – 6
(8) N2 = 8 (number of neutrons in C-14)
11.
(A)
(B)
(C)
(D)
(E)
What particle can be emitted when 15P-32 decays to 16S-32?
alpha
electron
neutron
gamma
proton
11A. (B) since the number of nucleons remains constant, and the atomic number increases by one, this
is a beta reaction.
12.
(A)
(B)
(C)
(D)
(E)
The binding energy of a nucleus is
the energy needed to remove one of the electrons
the average energy of any nucleon
the energy needed to separate all the nucleons
the mass of the nucleus times c2
the mass of the nucleus divided by c2
3|Page
CHEMISTRY
MR. SURRETTE
VAN NUYS HIGH SCHOOL
12A. (C) the energy needed to separate all the nucleons.
13.
(A)
(B)
(C)
(D)
(E)
If controlled fusion becomes feasible, which would be the main source of fuel:
corn oil
air
coal
water
petroleum
13A. (D) water
14.
(A)
(B)
(C)
(D)
(E)
Nuclear fusion involves combining the nuclei of:
low atomic numbers
metals
non-metals
noble gases
high atomic numbers
14A. (A) low atomic numbers
15.
(A)
(B)
(C)
(D)
(E)
The function of the moderator material in a nuclear fission reactor is to:
absorb neutrons
create new neutrons
accelerate neutrons
decelerate neutrons
destroy neutrons
15A. (D) decelerate neutrons
16. The energy released per fission event of U-235 is 208 MeV. This reaction is 30% efficient.
Approximately how many fission events occur in one second to provide the 2.00 kW electrical power
needs of a typical home? (1 eV = 1.6 x 10-19 J)
16A.
(1) Energy = (0.30)(208 x 106 eV)
(2) Energy = 6.24 x 107 eV
(3) 6.24 x 107 eV (1.6 x 10-19 J / 1 eV)
(4) Energy = 9.984 x 10-12 J
(5) Rate = (2000 J / 1 sec)(1 event / 9.984 x 10-12 J)
(6) Rate = 2.00 x 1014 events / sec
17.
(A)
(B)
(C)
(D)
(E)
Cadmium control rods used in a nuclear fission reactor serve what purpose:
absorb neutrons
create new neutrons
accelerate neutrons
decelerate neutrons
destroy neutrons
4|Page
CHEMISTRY
MR. SURRETTE
VAN NUYS HIGH SCHOOL
17A. (A) absorb neutrons
18. A proton and a neutron combine in a fusion process to form a stable deuterium nucleus. Which of
the following statements best applies to the mass of the deuterium nucleus?
(A) less than the sum of the proton and neutron masses
(B) equal to the sum of the proton and neutron masses
(C) greater than the sum of the proton and neutron masses
(D) equal to twice the proton mass
(E) equal to half the proton mass
18A. (A) less than the sum of the proton and neutron masses.
5|Page
CHEMISTRY