Question 1

Nuclear fusion: How does the mass of the products of a nuclear fusion reaction compare to the mass of the original elements?

Accepted Answer

A)  The mass of the products is greater than the mass of the original elements. 
B)  The mass of the products is less than the mass of the original elements. 
C)  The mass of the products is equal to the mass of the original elements. 
D)  The mass of the products is unrelated to the mass of the original elements. 
A)  The mass of the products is greater than the mass of the original elements. 
B)  The mass of the products is less than the mass of the original elements. 
C)  The mass of the products is equal to the mass of the original elements. 
D)  The mass of the products is unrelated to the mass of the original elements. B

Question 2

Nuclear reactions: For the missing product X in the reaction
neutron +   U →   Ba + X + 3 neutrons
determine the atomic mass and atomic number of X, and write X in the standard form. It is NOT necessary to identify which atom X is.

Accepted Answer

A = 92, Z = 36,   X

Question 3

Nuclear binding energy: The iron nucleus has the greatest binding energy of any nucleus.

Accepted Answer

A) True 
 B)False  False

Question 4

Properties of the nucleus: What would be the expected radius of the nucleus of   Sr?

Accepted Answer

A)  4.0 fm 
B)  1.2 fm 
C)  5.4 fm 
D)  0.11 pm 
E)  0.54 pm 
A)  4.0 fm 
B)  1.2 fm 
C)  5.4 fm 
D)  0.11 pm 
E)  0.54 pm

Question 5

Radioactive decay: The half-life of cobalt-60 is 5.3 years, while that of strontium-90 is 28 years. Suppose that samples of cobalt-60 and strontium-90 are such that they initially have the same activity (number of decays per second). What is true about the initial numbers of cobalt-60 and strontium-90 nuclei in these samples?

Accepted Answer

A)  There are more strontium-90 than cobalt-60 nuclei. 
B)  There are equal numbers of cobalt-60 and strontium-90 nuclei. 
C)  There are more cobalt-60 than strontium-90 nuclei. 
D)  It is not possible to compare numbers of nuclei without knowing the masses of the samples. 
A)  There are more strontium-90 than cobalt-60 nuclei. 
B)  There are equal numbers of cobalt-60 and strontium-90 nuclei. 
C)  There are more cobalt-60 than strontium-90 nuclei. 
D)  It is not possible to compare numbers of nuclei without knowing the masses of the samples.

Question 6

Biomedicine: The radioactive nuclei 60Co are widely used in medical applications. This nucleus undergoes beta decay, and the total energy of the decay process is 2.82 MeV per decay event. The half-life of this nucleus is 272 days. Suppose that a patient is given a dose of 6.9 µCi of 60Co. If all of this material decayed while in the patient's body, what would be the total energy deposited there? (1 Ci = 3.70 × 1010 decays/s)

Accepted Answer

A)  11 J 
B)  8.6 GJ 
C)  3.9 J 
D)  24 J 
E)  4.15 MJ 
A)  11 J 
B)  8.6 GJ 
C)  3.9 J 
D)  24 J 
E)  4.15 MJ

Question 7

Nuclear fission: If a 2.0-MeV neutron released in a fission reaction loses half of its energy in each moderator collision, how many collisions are needed to reduce its energy to (1/25) eV?

Accepted Answer

A)  6 
B)  18 
C)  26 
D)  30 
E)  4 
A)  6 
B)  18 
C)  26 
D)  30 
E)  4

Question 8

Nuclear binding energy: Going from medium mass nuclei to heavy nuclei, the average binding energy per nucleon

Accepted Answer

A)  decreases. 
B)  behaves randomly with no clear pattern. 
C)  does not change. 
D)  increases. 
E)  doubles. 
A)  decreases. 
B)  behaves randomly with no clear pattern. 
C)  does not change. 
D)  increases. 
E)  doubles.

Question 9

Radioactive decay: An air sample is contaminated with 15O, which has a half-life of 2.03 min. One possible way to minimize its hazard is to pass it through a long pipe to allow it to decay inside the pipe until it can be safely released into the atmosphere. If the oxygen moves at a speed of 1.1 m/s in the pipe, how long must the pipe be for the sample to have decayed to 3.0% of its original activity just as it leaves the pipe?

Accepted Answer

A)  680 m 
B)  8.0 m 
C)  7.0 m 
D)  2.0 m 
A)  680 m 
B)  8.0 m 
C)  7.0 m 
D)  2.0 m

Question 10

Nuclear reactions: In the nuclear reaction
n +   U → X + 2e-
n is a neutron and e- is an electron, and the neutrinos have not been shown. Determine the atomic mass and atomic number of the missing nuclear product X, and write X in the standard form. It is NOT necessary to identify which atom X is.

Accepted Answer

Question 11

Radioactive dating: An archaeologist finds the 14C in a sample of   of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of 14C is 5730 y. How old is the sample?

Accepted Answer

A)  12,200 y 
B)  8460 y 
C)  25,100 y 
D)  12,600 y 
A)  12,200 y 
B)  8460 y 
C)  25,100 y 
D)  12,600 y

Question 12

Reaction energy: Calculate the reaction energy (Q value) for the reaction 7Li + 1H → 4He + 4He, given the following masses: 7Li: 7.016005 u
1H: 1.007825 u
4He: 4.002603 u
(1 u = 931.5 MeV/c2)

Accepted Answer

A)  13.35 MeV 
B)  13.57 MeV 
C)  15.37 MeV 
D)  17.35 MeV 
E)  17.53 MeV 
A)  13.35 MeV 
B)  13.57 MeV 
C)  15.37 MeV 
D)  17.35 MeV 
E)  17.53 MeV

Question 13

Nuclear fusion: Two deuterium nuclei,   H, fuse to produce a helium nucleus,   H, and a neutron. A neutral deuterium atom has a mass of 2.014102 u; a neutral helium atom has a mass of 3.016030 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007276 u. How much energy is released in the process? (1 u = 931.494 MeV/c2)

Accepted Answer

A)  3.27 MeV 
B)  3.57 MeV 
C)  4.00 MeV 
D)  4.50 MeV 
E)  5.68 MeV 
A)  3.27 MeV 
B)  3.57 MeV 
C)  4.00 MeV 
D)  4.50 MeV 
E)  5.68 MeV

Question 14

Nuclear fusion: Two deuterium nuclei,   H, fuse to produce a tritium nucleus,   H, and a hydrogen nucleus. A neutral deuterium atom has a mass of 2.014102 u; a neutral tritium atom has a mass of 3.016049 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007276 u. How much energy is released in the process? (1 u = 931.494 MeV/c2)

Accepted Answer

A)  3.03 MeV 
B)  3.53 MeV 
C)  4.03 MeV 
D)  4.53 MeV 
E)  6.58 MeV 
A)  3.03 MeV 
B)  3.53 MeV 
C)  4.03 MeV 
D)  4.53 MeV 
E)  6.58 MeV

Question 15

Nuclear binding energy: Plutonium-239 decays into uranium-235 plus an alpha particle. The energy released in the process is 5.24 MeV. Given the following mass values   He: 4.002603 u   U: 235.043924 u what is the mass of   Pu in atomic mass units? (1 u = 931.494 MeV/c2)

Accepted Answer

A)  239.05215 u 
B)  239.02775 u 
C)  239.00189 u 
D)  238.99919 u 
E)  238.98884 u 
A)  239.05215 u 
B)  239.02775 u 
C)  239.00189 u 
D)  238.99919 u 
E)  238.98884 u

Question 16

Nuclear fission: An excited   U* nucleus undergoes fission into two fragments, as shown:   U* →   Ba +   Kr The following atomic masses are known:   Kr: 91.926270 u   Ba: 143.922845 u   U*: 236.045563 u
What is the reaction energy, in MeV, for this process? (1 u = 1.6605 × 10-27 kg = 931.5 MeV/c2)

Accepted Answer

A)  150 MeV 
B)  160 MeV 
C)  170 MeV 
D)  180 MeV 
E)  190 MeV 
A)  150 MeV 
B)  160 MeV 
C)  170 MeV 
D)  180 MeV 
E)  190 MeV

Question 17

Biomedicine: A 70-kg laboratory technician absorbs 2.9 mJ of 0.50-MeV gamma rays in a workday. How many gamma-ray photons does the technician absorb in a workday?

Accepted Answer

A)  3.6 × 1010 
B)  3.6 × 109 
C)  3.6 × 108 
D)  1.0 × 109 
E)  1.0 × 108 
A)  3.6 × 1010 
B)  3.6 × 109 
C)  3.6 × 108 
D)  1.0 × 109 
E)  1.0 × 108

Question 18

Radioactive dating: An ancient rock is found to contain 40Ar gas, indicating that   of the 40K in the rock has decayed since the rock solidified. Any argon would have boiled out of liquid rock. The half-life of 40K is 1.25 billion years. How long ago did the rock solidify?

Accepted Answer

A)  2.6 billion years 
B)  0.50 billion years 
C)  1.8 billion years 
D)  0.30 billion years 
A)  2.6 billion years 
B)  0.50 billion years 
C)  1.8 billion years 
D)  0.30 billion years

Question 19

Properties of the nucleus: A certain nucleus containing 8 protons and 7 neutrons has a density ρ. Which of the following values would be closest to the expected value of the density of a nucleus having 51 protons and 69 neutrons?

Accepted Answer

A)  1.00 ρ 
B)  1.85 ρ 
C)  2.00 ρ 
D)  2.14 ρ 
E)  8.00 ρ 
A)  1.00 ρ 
B)  1.85 ρ 
C)  2.00 ρ 
D)  2.14 ρ 
E)  8.00 ρ

Question 20

Radioactive dating: The radioactivity due to carbon-14 measured in a piece of a wood from an ancient site was found to produce 20 counts per minute from a given sample, whereas the same amount of carbon from a piece of living wood produced 160 counts per minute. The half-life of carbon-14, a beta emitter, is 5730 y. The age of the artifact is closest to

Accepted Answer

A)  5700 y. 
B)  12,000 y. 
C)  15,000 y. 
D)  17,000 y. 
E)  23,000 y. 
A)  5700 y. 
B)  12,000 y. 
C)  15,000 y. 
D)  17,000 y. 
E)  23,000 y.

Exam 34: Geometric Optics

Nuclear fusion: How does the mass of the products of a nuclear fusion reaction compare to the mass of the original elements?

Nuclear reactions: For the missing product X in the reaction neutron + U → Ba + X + 3 neutrons determine the atomic mass and atomic number of X, and write X in the standard form. It is NOT necessary to identify which atom X is.

Nuclear binding energy: The iron nucleus has the greatest binding energy of any nucleus.

Properties of the nucleus: What would be the expected radius of the nucleus of Sr?

Nuclear fission: If a 2.0-MeV neutron released in a fission reaction loses half of its energy in each moderator collision, how many collisions are needed to reduce its energy to (1/25) eV?

Nuclear binding energy: Going from medium mass nuclei to heavy nuclei, the average binding energy per nucleon

Nuclear reactions: In the nuclear reaction n + U → X + 2e- n is a neutron and e- is an electron, and the neutrinos have not been shown. Determine the atomic mass and atomic number of the missing nuclear product X, and write X in the standard form. It is NOT necessary to identify which atom X is.

Radioactive dating: An archaeologist finds the 14C in a sample of of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of 14C is 5730 y. How old is the sample?

Reaction energy: Calculate the reaction energy (Q value) for the reaction 7Li + 1H → 4He + 4He, given the following masses: 7Li: 7.016005 u 1H: 1.007825 u 4He: 4.002603 u (1 u = 931.5 MeV/c2)

Nuclear binding energy: Plutonium-239 decays into uranium-235 plus an alpha particle. The energy released in the process is 5.24 MeV. Given the following mass values He: 4.002603 u U: 235.043924 u what is the mass of Pu in atomic mass units? (1 u = 931.494 MeV/c2)

Nuclear fission: An excited U* nucleus undergoes fission into two fragments, as shown: U* → Ba + Kr The following atomic masses are known: Kr: 91.926270 u Ba: 143.922845 u U*: 236.045563 u What is the reaction energy, in MeV, for this process? (1 u = 1.6605 × 10-27 kg = 931.5 MeV/c2)

Biomedicine: A 70-kg laboratory technician absorbs 2.9 mJ of 0.50-MeV gamma rays in a workday. How many gamma-ray photons does the technician absorb in a workday?

Radioactive dating: An ancient rock is found to contain 40Ar gas, indicating that of the 40K in the rock has decayed since the rock solidified. Any argon would have boiled out of liquid rock. The half-life of 40K is 1.25 billion years. How long ago did the rock solidify?

Properties of the nucleus: A certain nucleus containing 8 protons and 7 neutrons has a density ρ. Which of the following values would be closest to the expected value of the density of a nucleus having 51 protons and 69 neutrons?

Motion Along a Straight Line

Motion in Two or Three Dimensions

Newtons Laws of Motion

Applying Newtons Laws

Work and Kinetic Energy

Potential Energy and Energy Conservation

Momentum, Impulse, and Collisions

Rotation of Rigid Bodies

Dynamics of Rotational Motion

Equilibrium and Elasticity

Fluid Mechanics

Gravitation

Periodic Motion

Mechanical Waves

Sound and Hearing

Temperature and Heat

Thermal Properties of Matter

The First Law of Thermodynamics

The Second Law of Thermodynamics

Electric Charge and Electric Field

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current, Resistance, and Electromotive Force

Direct-Current Circuits

Magnetic Field and Magnetic Forces

Sources of Magnetic Field

Electromagnetic Induction

Inductance

Alternating Current

Electromagnetic Waves Optics

The Nature and Propagation of Light

Interference

Filters

Radioactive dating: An archaeologist finds the ¹⁴C in a sample of of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of ¹⁴C is 5730 y. How old is the sample?

Reaction energy: Calculate the reaction energy (Q value) for the reaction 7Li + 1H → 4He + 4He, given the following masses: 7Li: 7.016005 u 1H: 1.007825 u 4He: 4.002603 u (1 u = 931.5 MeV/c²)

Nuclear binding energy: Plutonium-239 decays into uranium-235 plus an alpha particle. The energy released in the process is 5.24 MeV. Given the following mass values He: 4.002603 u U: 235.043924 u what is the mass of Pu in atomic mass units? (1 u = 931.494 MeV/c²)

Nuclear fission: An excited U* nucleus undergoes fission into two fragments, as shown: U* → Ba + Kr The following atomic masses are known: Kr: 91.926270 u Ba: 143.922845 u U*: 236.045563 u What is the reaction energy, in MeV, for this process? (1 u = 1.6605 × 10^-27 kg = 931.5 MeV/c²)

Radioactive dating: An ancient rock is found to contain ⁴⁰Ar gas, indicating that of the ⁴⁰K in the rock has decayed since the rock solidified. Any argon would have boiled out of liquid rock. The half-life of ⁴⁰K is 1.25 billion years. How long ago did the rock solidify?