NuclearMCQ5.

Exam

Name___________________________________


MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which one of the following statements about the atomic nucleus is accurate? 1)
A) The nucleus is held together mostly by the electrical and gravitational forces.
B) Large nuclei are denser than light nuclei.
C) All nuclei have nearly the same density.
D) A nucleus containing 20 nucleons will have approximately twice the radius as a nucleus
containing 10 nucleons.
E) Heavy nuclei most easily undergo nuclear fusion.

2) Nucleus "a" contains 5 protons and 5 neutrons and has radius R. The radius of nucleus "b", 2)
which contains 35 protons and 45 neutrons, is closest to:
A) 8R B) R C) 2R D) 1.4R E) 4R

3) The decay rate of an isotope is initially R 0 but after one half-life has gone by, the rate is R 0/2. At 3)
the end of the next half-life, the decay rate will be:
A) 0 B) R/4 C) R/e D) R/2 E) R/e 2

Situation 43.1
Two sealed boxes each start out containing 100.0 g of radioactive samples and contain nothing else. The isotope in one
box has a half-life of 1.00 hr, while the isotope in the other box has a half-life of 2.00 hr. Both isotope samples have the
same initial decay rate and both are beta-minus emitters. Each box is on a laboratory scale, and the boxes themselves
have negligible weight.

4) In Situation 43.1, after 4.00 hr have elapsed, the ratio of the scale reading for the 2.00-hr isotope 4)
to the scale reading of the 1.00-hr isotope will be closest to:
A) 2 B) 16 C) 1 D) 4 E) 8

5) In Situation 43.1, after 4.00 hr have elapsed, the ratio of the decay rate of the 2.00-hr isotope to 5)
the decay rate of the 1.00-hr isotope will be closest to:
A) 1 B) 2 C) 4 D) 16 E) 8

6) The following masses are known: 6)

1n 1.008665 u
0

1H 1.007825 u
1

7 Li 7.016004 u
3


The binding energy of 7 Li, in MeV, is closest to:
3
A) 48 B) 56 C) 39 D) 52 E) 43


1

, 7) The binding energy per nucleon for 60 Co, calculated from the liquid drop model, in MeV, is 7)
27
closest to:
A) 8.4 B) 8.8 C) 8.0 D) 8.6 E) 8.2


8) A proton is projected at a stationary 62 Ni aluminum target. The proton momentarily comes to a 8)
38
halt at a distance from the center of an aluminum nucleus, equal to twice the nuclear radius.
Assume that the nucleus retains its spherical shape and that the nuclear force on the proton is
negligible. The initial kinetic energy of the proton, in MeV, is closest to:
A) 5.8 B) 12 C) 1.9 D) 3.8 E) 8.6


9) Rubidium 87 Rb is a naturally occurring nuclide that undergoes beta-minus decay. The nuclide, 9)
37
which is the product of the decay, is:
A) 87 Kr B) 88 Rb C) 87 Kr D) 87 Sr E) 87 Sr
38 37 36 38 36



10) Naturally occurring tellurium, 123 Te, transforms by electron capture, according to the reaction 10)
52


123 Te + e - → X +v
e
52


The product nuclide, denoted by X, is:
A) 123 I B) 123 Sb C) 123 Te D) 123 Sb E) 123 I
53 53 52 51 51



11) Neodymium 144Nd is a nuclide that undergoes alpha decay. The nuclide that is the product of 11)
the decay is:
A) 148 Sm B) 142 Ba C) 140 Pr D) 140 Ce E) 146 Gd
62 56 559 58 64



12) Scandium 44Sc decays by emitting a positron. The nuclide that is the product of the decay is: 12)
A) 44 Ti B) 43 Sc C) 44 Ca D) 45 Sc E) 43 Ca
22 21 20 21 21



13) Neptunium 239 Np has a decay constant of 3.40 × 10-6 s-1. A 3.0-mg sample of Np-239 is 13)
93
prepared. The activity of the Np-239 sample, in Ci, is closest to:
A) 70 B) 220 C) 700 D) 2200 E) 22




2