Deck 29: Nuclear Physics

Question 1

What is the symbol for the nuclide with 38 protons and 50 neutrons?

A) $\begin{array}{r}88 \\ 50\end{array}$
B) $\begin{array}{r}88 \\ \quad 58\end{array}$
C) $\mathrm{Sn}_{50}^{38}$
D) $\begin{array}{r}50 \\ 38\end{array}$

Answer 1

$\begin{array}{r}88 \\ \quad 58\end{array}$

Question 2

What is the symbol for the nuclide with 46 protons and 92 neutrons?

A) $\mathrm{U}^{132}$
B) $\quad \begin{gathered}138 \\ 46\end{gathered}$
C) $\mathrm{U}_{92}^{46}$
D) $\mathrm{Pd} \frac{92}{46}$

Answer 2

$\quad \begin{gathered}138 \\ 46\end{gathered}$

Question 3

One mole of $\mathrm{Al}_{13}^{27}$ has a mass of approximately

A) $14 \mathrm{~g}$
B) $27 \mathrm{~g}$
C) $20 \mathrm{~g}$
D) $40 \mathrm{~g}$
E) $13 \mathrm{~g}$

Answer 3

$27 \mathrm{~g}$

Question 4

How many atoms are in one gram of $\mathrm{Al}_{13}^{27}$ ?

A) $6.02 \times 10^{22}$
B) $1.51 \times 10^{23}$
C) $2.23 \times 10^{22}$
D) $2.23 \times 10^{25}$
E) $1.63 \times 10^{25}$

Question 5

What nuclide has 14 protons and 16 neutrons?

A) $14 \mathrm{O}$
B) $30 \mathrm{~S}$
C) $16 \mathrm{~S}$
D) $30 \mathrm{Si}$

Question 6

One mole of $40 \mathrm{Ar}(\mathrm{Z}=18)$ has about what mass?

A) $22 \mathrm{~kg}$
B) $18 \mathrm{~g}$
C) $22 \mathrm{~g}$
D) $40 \mathrm{~g}$
E) $40 \mathrm{~kg}$

Question 7

One pg (picogram) of $40 \mathrm{~K}$ has how many nuclei?

A) $1.5 \times 1010$
B) $6.0 \times 1011$
C) $3.0 \times 1011$
D) $6.0 \times 1017$
E) $1.5 \times 1022$

Question 8

What is the radius of a nuclide with mass number 190 ?

A) $6.9 \mathrm{fm}$
B) $0.19 \mathrm{fm}$
C) $190 \mathrm{fm}$
D) $5.7 \mathrm{fm}$
E) $4.8 \mathrm{fm}$

Question 9

What is the volume of the $U_{92}^{238}$ nucleus?

A) $1.7 \times 10-42 \mathrm{~m}^{3}$
B) $6.7 \times 10-43 \mathrm{~m}^{3}$
C) $5.2 \times 10^{-42} \mathrm{~m}^{3}$
D) $1.2 \times 10^{-12} \mathrm{~m}^{3}$
E) $1.6 \times 10^{-42} \mathrm{~m}^{3}$

Question 10

What is the density of the $238 \mathrm{U}$ nucleus?

A) $3.2 \times 10^{14} \mathrm{~kg} / \mathrm{m}^{3}$
B) $1.0 \times 10^{3} \mathrm{~kg} / \mathrm{m}^{3}$
C) $2.38 \times 10^{5} \mathrm{~kg} / \mathrm{m}^{3}$
D) $9.6 \times 1014 \mathrm{~kg} / \mathrm{m}^{3}$
E) $2.3 \times 1017 \mathrm{~kg} / \mathrm{m}^{3}$

Question 11

In the reaction $n+12 C \rightarrow \alpha+$ ?, what is the unknown product nucleus?

A) $9 \mathrm{~B}$
B) $9 \mathrm{C}$
C) $13 \mathrm{C}$
D) $9 \mathrm{Be}$
E) $10 \mathrm{~B}$

Question 12

In the reaction $4 \mathrm{He}+{ }^{9} \mathrm{Be} \rightarrow \mathrm{n}+{ }^{12} \mathrm{C}$ , how much energy is released or absorbed? The masses of the neutral atoms are as follows: the mas of $4 \mathrm{He}$ is $4.0026033 \mathrm{u}$ , the mass of ${ }^{9} \mathrm{Be}$ is $9.0121831 \mathrm{u}$ , the mass of $\mathrm{n}$ is $1.0086649 \mathrm{u}$ , and the mass of $12 \mathrm{C}$ is $12.0000000 \mathrm{u}$ .

A) $5.70 \mathrm{MeV}$ released
B) $4.21 \mathrm{MeV}$ released
C) $4.21 \mathrm{MeV}$ absorbed
D) $5.70 \mathrm{MeV}$ absorbed
E) $6.34 \mathrm{MeV}$ released

Question 13

What is the binding energy per nucleon for ${ }^{12} \mathrm{C}$ ?

A) $7.68 \mathrm{MeV}$
B) $46.1 \mathrm{MeV}$
C) $104 \mathrm{MeV}$
D) $137 \mathrm{MeV}$
E) $92.2 \mathrm{MeV}$

Question 14

What are the approximate binding energies per nucleon (in $\mathrm{MeV}$ ) around $\mathrm{A}=60$ and $\mathrm{A}=240$ , respectively?

A) $9.4,7.0$
B) $7.0,9.4$
C) $7.0,8.0$
D) $7.6,8.7$
E) $8.7,7.6$

Question 15

What is the binding energy of an alpha particle?

A) $28.3 \mathrm{MeV}$
B) $50.0 \mathrm{MeV}$
C) $2.20 \mathrm{MeV}$
D) $21.2 \mathrm{MeV}$

Question 16

What is the mass defect of an alpha particle?

A) $0.03147 \mathrm{u}$
B) $0.30377 \mathrm{u}$
C) $0.02928 \mathrm{u}$
D) $0.03038 \mathrm{u}$

Question 17

When 241 Am decays by emitting an alpha particle of kinetic energy $5.5 \mathrm{MeV}$ , what is the recoil energy of the daughter nucleus?

A) $0.091 \mathrm{MeV}$
B) $0.093 \mathrm{MeV}$
C) $1.3 \mathrm{MeV}$
D) $5.5 \mathrm{MeV}$
E) $0.88 \mathrm{MeV}$

Question 18

The isotope $A_{28} 1$ decays by beta-minus decay. What is the daughter nucleus?

A) $\mathrm{Si}_{28}$
B) $\mathrm{Si}_{27}$
C) $\mathrm{Mg}_{28}$
D) $\mathrm{A}_{27} 1$
E) $\mathrm{Na}_{24}$

Question 19

The isotope $\mathrm{A}_{26} 1$ decays by beta-plus decay. What is the daughter nucleus?

A) $26 \mathrm{Al}$
B) $26 \mathrm{Mg}$
C) $27 \mathrm{Al}$
D) $25 \mathrm{Al}$
E) $26 \mathrm{Si}$

Question 20

Barium-137 emits a gamma ray in the decay from an excited state $\left({ }^{137} \mathrm{Ba}^{*}\right)$ . What is the resulting daughter nuclide?

A) $136 \mathrm{Cs}$
B) $137 \mathrm{La}$
C) $137 \mathrm{Ba}$
D) $137 \mathrm{Cs}$
E) $136 \mathrm{Ba}$

Question 21

The half-life of 30P is 2.50 minutes. If a sample of 30P has $1.60 \times 1010$ nuclei present initially, how many remain after 10.0 minutes?

A) $0.050 \times 1010$
B) $0.400 \times 1010$
C) $0.200 \times 1010$
D) $0.100 \times 1010$
E) $0.800 \times 1010$

Question 22

The half-life of $30 \mathrm{P}$ is 2.50 minutes. If a sample of $30 \mathrm{P}$ has $1.60 \times 10^{10}$ nuclei present, what is its activity?

A) $1.6 \times 10^{9} \mathrm{~Bq}$
B) $6.4 \times 10^{9} \mathrm{~Bq}$
C) $1.6 \times 10^{10} \mathrm{~Bq}$
D) $7.4 \times 10^{7} \mathrm{~Bq}$
E) $4.6 \times 10^{7} \mathrm{~Bq}$

Question 23

A sample contains $1.000 \times 10^{-3} \mathrm{~g}$ of $40 \mathrm{~K}$ . The half-life of $40 \mathrm{~K}$ is $1.250 \times 10^{9}$ years. What is the activity of the sample?

A) $265.0 \mathrm{~Bq}$
B) $382.0 \mathrm{~Bq}$
C) $3300 \mathrm{~Bq}$
D) $3.000 \mathrm{~Bq}$
E) $1250 \mathrm{~Bq}$

Question 24

What is the mass of $25.0 \mathrm{mCi}$ of technetium- $99 \mathrm{~m}$ (Tc99m), which has a half-life of $6.00 \mathrm{~h}$ ?

A) $4.74 \mathrm{ng}$
B) $3.29 \mathrm{ng}$
C) $1.05 \mathrm{ng}$
D) $50.7 \mathrm{pg}$
E) $25.0 \mathrm{mg}$

Question 25

If a $70 \mathrm{~kg}$ person received a dose of $3.2 \mathrm{mGy}$ of gamma rays of $\mathrm{RBE}=0.80$ , what is the biologically equivalent dose in rem?

A) 0.18
B) 18
C) 0.0026
D) 0.26
E) 0.012

Question 26

If a $60 \mathrm{~kg}$ person received a biologically equivalent dose of 1.7 rem of radiation with an RBE of 1.1, what was the total energy absorbed by the person?

A) $0.93 \mathrm{~J}$
B) $0.26 \mathrm{~J}$
C) $1.7 \mathrm{~J}$
D) $1.5 \mathrm{~J}$
E) $0.015 \mathrm{~J}$

Question 27

A beam of gamma rays strikes a lead target with a half-value layer of $0.40 \mathrm{~cm}$ . What fraction of the photons in the beam will penetrate to a depth of $1.20 \mathrm{~cm}$ or more?

A) 0.250
B) 0.500
C) 0.333
D) 0.125
E) 0.400

Question 28

In the fission reaction $\mathrm{n}+\mathrm{U}_{92}^{235} \rightarrow \mathrm{Ba}_{56}^{141}+$ ? $+4 \mathrm{n}$ , what are the $\mathrm{Z}$ and $\mathrm{A}$ for the unknown fission product?

A) 36,91
B) 37,90
C) 36,90
D) 35,94
E) 37,91

Question 29

The fusion reaction $2 \mathrm{H}+3 \mathrm{H} \rightarrow 4 \mathrm{He}+\mathrm{n}$ releases $17.6 \mathrm{MeV}$ of energy. The mass of $2 \mathrm{H}$ is $2.01410 \mathrm{u}$ , the mass of $4 \mathrm{He}$ is $4.00260 \mathrm{u}$ , and the mass of the neutron is $1.00866 \mathrm{u}$ . What is the mass of $3 \mathrm{H}$ ?

A) $3.0349 \mathrm{u}$
B) $2.9998 \mathrm{u}$
C) $3.0422 \mathrm{u}$
D) $3.0161 \mathrm{u}$
E) $2.9972 \mathrm{u}$

Question 30

What is the ratio of radii of the nuclides $\mathrm{U}_{92}^{238}$ and $\mathrm{Ca}_{20}{ }_{20}$ ?

A) 1.81
B) 2.44
C) 1.66
D) 5.95

Question 31

It is common to illustrate the density of nuclear matter by discussing the mass of a teaspoon of nuclear material. The volume of a teaspoon is about $5 \mathrm{~cm}^{3}$ . Using the relationship $r=(1.2 \mathrm{fm}) \mathrm{A}^{1 / 3}$ together with the mass of a proton, $1.67 \times 10^{-27} \mathrm{~kg}$ , estimate the mass of a teaspoon of nuclear material.

A) $3.8 \times 1011 \mathrm{~kg}$
B) $1.15 \times 1012 \mathrm{~kg}$
C) $1.53 \times 1012 \mathrm{~kg}$
D) $9.6 \times 1011 \mathrm{~kg}$

Question 32

A neutron star has approximately the same density as nuclear material. A typical neutron star has a radius of $8.0 \mathrm{~km}$ . Using the relationship $\mathrm{r}=(1.2 \mathrm{fm}) \mathrm{A} 1 / 3$ together with the mass of a neutron, $1.67 \times 10^{-27} \mathrm{~kg}$ , estimate the mass of a neutron star.

A) $0.65 \times 10^{30}\mathrm{~kg}$
B) $0.16 \times 10^{30}\mathrm{~kg}$
C) $1.5 \times 10^{30} \mathrm{~kg}$
D) $0.49 \times 10^{30}\mathrm{~kg}$

Question 33

What is the radius of the nuclide $U_{92}^{238}$ ?

A) $1.8 \mathrm{fm}$
B) $290 \mathrm{fm}$
C) $5.4 \mathrm{fm}$
D) $7.4 \mathrm{fm}$

Question 34

Carbon-14 has a half-life of 5730 years. You discover a single carbon-14 nucleus in your laboratory. What is the probability that it will decay in the next 24 hours?

A) $4.8 \times 10^{-7}$
B) $4.9 \times 10^{-7}$
C) $3.3 \times 10^{-7}$
D) It cannot be known unless the age of the nucleus is known.

Question 35

How many neutrons are produced in the following induced fission reaction?
$\mathrm{n}_{1}+\mathrm{U}_{92}^{238} \rightarrow \mathrm{S}_{38}^{95} \mathrm{r}+\mathrm{X}_{54}^{139} \mathrm{e}+$ neutrons

A) 0
B) 1
C) 3
D) 2

Question 36

Which of the following nuclear reactions is forbidden?

A) $\mathrm{Li}_{3}^{7}+\mathrm{He}_{2}^{3} \rightarrow \mathrm{p}_{1}^{1}+2 \mathrm{He}_{2}^{4}$
B) $\mathrm{n}_{1}+\mathrm{U}_{92}^{235} \rightarrow \mathrm{S}_{50}^{132} \mathrm{n}+\mathrm{M}_{42}^{101} \mathrm{o}+3 \mathrm{n}_{1}$
C) $\mathrm{He}_{2}^{4}+\mathrm{H}_{1}^{3} \rightarrow \mathrm{Li}_{3}^{7}$
D) $\mathrm{Li}_{3}^{7}+\mathrm{H}_{1}^{1} \rightarrow 2 \mathrm{He}_{2}^{4}$