Question 1

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years

Accepted Answer

A)  0.147 mg 
B)  0.296 mg 
C)  0.725 mg 
D)  6.77 mg 
E)  1.90 mg

Question 2

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed 
${ }_{2}^{4} \mathrm{He}+{ }_{4}^{9} \mathrm{Be} \rightarrow{ }_{0}^{1} \mathrm{n}+\_\_\_\_\_\_$

Accepted Answer

A)  ${ }_{6}^{12} \mathrm{C}$ 
B)  ${ }_{3}^{5} \mathrm{Li}$ 
C)  ${ }_{3}^{8} \mathrm{Li}$ 
D)  ${ }_{5}^{10} \mathrm{~B}$ 
E)  ${ }_{5}^{12} \mathrm{~B}$

Question 3

The mass of a nucleus is always less than the sum of the masses of the nucleons.

Accepted Answer

A) True 
 B)False

Question 4

When lead-209 undergoes beta decay the balanced nuclear equation for this reaction is: ${ }_{82}^{209} \mathrm{~Pb} \rightarrow{ }_{83}^{209} \mathrm{Bi}+{ }_{-1}^{0} \beta$

Accepted Answer

A) True 
 B)False

Question 5

Decay of silicon-27 by positron emission yields

Accepted Answer

A)  magnesium-23. 
B)  sulfur-31. 
C)  phosphorus-27. 
D)  silicon-26. 
E)  aluminum-27.

Question 6

Which one of the following statements about fission and fusion is false

Accepted Answer

A)  Fission occurs among the heaviest isotopes, whereas fusion occurs more readily for light isotopes. 
B)  For a fission reaction the mass defect (Dm) is negative, whereas for fusion Dm is positive. 
C)  In order for fusion reactions to occur, temperatures must be in the millions of degrees. 
D)  The fission of Pu-239 atoms produces a great number of isotopes of a large number of elements. 
E)  Neutron-induced fission processes can occur at room temperature, rather than at millions of degrees.

Question 7

The fundamental unit of radioactivity is the ______ .

Accepted Answer

A)  Einstein 
B)  Rad 
C)  Chang 
D)  Curie 
E)  None of the above

Question 8

A rock contains 0.37 mg of Pb-206 and 0.95 mg of U-238. Approximately how many U-238 atoms were in the rock when it was formed billions of years ago (The half life for 238U $\rarr$ 206Pb is 4.5 * 109 yr.)

Accepted Answer

A)  1.32 atoms 
B)  5.8 * 10-6 atoms 
C)  2.4 * 1018 atoms 
D)  3.5 * 1018 atoms 
E)  3.5 * 1021 atoms

Question 9

Alpha particles are identical to

Accepted Answer

A)  protons. 
B)  helium atoms. 
C)  hydrogen atoms. 
D)  helium nuclei. 
E)  electrons.

Question 10

The dose unit of ionizing radiation is called the rad. The rad is defined in terms of

Accepted Answer

A)  the half-life of a radioisotope. 
B)  the energy deposited per gram of an object. 
C)  the biological damage produced. 
D)  the accumulation of fission products. 
E)  the number of ions per centimeter.

Question 11

List the number of protons, neutrons, and nucleons (protons + neutrons), in that order, for an isotope with the symbol: $^{137}_{~~56}$Ba

Accepted Answer

A)  56, 81, 137 
B)  81, 56, 137 
C)  56, 137, 193 
D)  137, 56, 193 
E)  81, 137, 218

Question 12

Both H2O and D2O can be used as moderators to slow neutrons in nuclear reactors.

Accepted Answer

A) True 
 B)False

Question 13

What fraction of radioactive atoms remains in a sample after six half-lives

Accepted Answer

A)  zero 
B)  1/6 
C)  1/16 
D)  1/32 
E)  1/64

Question 14

The only stable isotope of aluminum is aluminum-27. What type of radioactive decay should be expected from ${ }_{13}^{28} \mathrm{Al}$

Accepted Answer

A)  ${ }_{1}^{1} \mathrm{H}$ 
B)  ${ }_{0}^{1} \text{n}$ 
C)  ${ }_{-1}^{~~~0} \beta$ 
D)  ${ }_{+1}^{~~~0} \beta$ 
E)  ${ }_{2}^{4} \mathrm{He}$

Question 15

Complete and balance the nuclear equation ${ }_{0}^{1} \mathrm{n}+{ }_{92}^{235} \mathrm{U} \rightarrow{ }_{35}^{87} \mathrm{Br}+3{ }_{0}^{1} \mathrm{n}+$ _______

Accepted Answer

A)  ${ }_{57}^{18} L a$ 
B)  ${ }_{57}^{146} \mathrm{La}$ 
C)  ${ }_{54}^{145} \mathrm{Xe}$ 
D)  ${ }_{54}^{143} X e$ 
E)  None of the above

Question 16

The type of nuclear process illustrated below is called electron capture. ${ }_{62}^{138} \mathrm{Sm}+{ }_{-1}^{0} \beta \longrightarrow{ }_{61}^{138} \mathrm{Pm}$

Accepted Answer

A) True 
 B)False

Question 17

Radioactive nitrogen-13 has a half-life of 10 minutes. After 40 minutes, how much of this isotope would remain in a sample that originally contained 96 mg

Accepted Answer

A)  6 mg 
B)  8 mg 
C)  10 mg 
D)  12 mg 
E)  None of the above

Question 18

Sodium-22 is more stable than sodium-23.

Accepted Answer

A) True 
 B)False

Question 19

Determine how much energy is released when thorium-230 decays according to ${ }^{230} \mathrm{Th} \rightarrow{ }^{4} \mathrm{He}+{ }^{226} \mathrm{Ra}$ . [Atomic masses: thorium-230 = 230.033127 amu; helium-4 = 4.002603 amu; radium-226 = 226.025403 amu]

Accepted Answer

A)  3.98 * 109 kJ/mol 
B)  4.60 * 108 kJ/mol 
C)  7.20 * 1011 kJ/mol 
D)  4.90 * 109 kJ/mol 
E)  7.15 * 1011 kJ/mol

Question 20

On a neutron number versus proton number plot, the nucleus of oxygen-15 lies below the belt of stability. In the radioactive decay of oxygen -15, what subatomic particle is emitted

Accepted Answer

A)  ${ }_{+1}^{0} e$ 
B)  ${ }_{0}^{1} n$ 
C)  ${ }_{2}^{4} \mathrm{He}$ 
D)  ${ }_{-1}^{0} e$ 
E)  None of the above

Exam 19: Nuclear Chemistry

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed ${ }_{2}^{4} \mathrm{He}+{ }_{4}^{9} \mathrm{Be} \rightarrow{ }_{0}^{1} \mathrm{n}+\_\_\_\_\_\_$

The mass of a nucleus is always less than the sum of the masses of the nucleons.

When lead-209 undergoes beta decay the balanced nuclear equation for this reaction is: ${ }_{82}^{209} \mathrm{~Pb} \rightarrow{ }_{83}^{209} \mathrm{Bi}+{ }_{-1}^{0} \beta$

Decay of silicon-27 by positron emission yields

Which one of the following statements about fission and fusion is false

The fundamental unit of radioactivity is the ______ .

A rock contains 0.37 mg of Pb-206 and 0.95 mg of U-238. Approximately how many U-238 atoms were in the rock when it was formed billions of years ago (The half life for ²³⁸U $\rarr$ ²⁰⁶Pb is 4.5 * 10⁹ yr.)

Alpha particles are identical to

The dose unit of ionizing radiation is called the rad. The rad is defined in terms of

List the number of protons, neutrons, and nucleons (protons + neutrons) , in that order, for an isotope with the symbol: $^{137}_{~~56}$ Ba

Both H₂O and D₂O can be used as moderators to slow neutrons in nuclear reactors.

What fraction of radioactive atoms remains in a sample after six half-lives

The only stable isotope of aluminum is aluminum-27. What type of radioactive decay should be expected from ${ }_{13}^{28} \mathrm{Al}$

Complete and balance the nuclear equation ${ }_{0}^{1} \mathrm{n}+{ }_{92}^{235} \mathrm{U} \rightarrow{ }_{35}^{87} \mathrm{Br}+3{ }_{0}^{1} \mathrm{n}+$ _______

The type of nuclear process illustrated below is called electron capture. ${ }_{62}^{138} \mathrm{Sm}+{ }_{-1}^{0} \beta \longrightarrow{ }_{61}^{138} \mathrm{Pm}$

Radioactive nitrogen-13 has a half-life of 10 minutes. After 40 minutes, how much of this isotope would remain in a sample that originally contained 96 mg

Sodium-22 is more stable than sodium-23.

Determine how much energy is released when thorium-230 decays according to ${ }^{230} \mathrm{Th} \rightarrow{ }^{4} \mathrm{He}+{ }^{226} \mathrm{Ra}$ . [Atomic masses: thorium-230 = 230.033127 amu; helium-4 = 4.002603 amu; radium-226 = 226.025403 amu]

On a neutron number versus proton number plot, the nucleus of oxygen-15 lies below the belt of stability. In the radioactive decay of oxygen -15, what subatomic particle is emitted

Exam 19: Nuclear Chemistry

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed 24He+49Be→01n+______{ }_{2}^{4} \mathrm{He}+{ }_{4}^{9} \mathrm{Be} \rightarrow{ }_{0}^{1} \mathrm{n}+\_\_\_\_\_\_24​He+49​Be→01​n+______

The mass of a nucleus is always less than the sum of the masses of the nucleons.

When lead-209 undergoes beta decay the balanced nuclear equation for this reaction is: 82209 Pb→83209Bi+−10β{ }_{82}^{209} \mathrm{~Pb} \rightarrow{ }_{83}^{209} \mathrm{Bi}+{ }_{-1}^{0} \beta82209​ Pb→83209​Bi+−10​β

Decay of silicon-27 by positron emission yields

Which one of the following statements about fission and fusion is false

The fundamental unit of radioactivity is the ______ .

A rock contains 0.37 mg of Pb-206 and 0.95 mg of U-238. Approximately how many U-238 atoms were in the rock when it was formed billions of years ago (The half life for 238U →\rarr→ 206Pb is 4.5 * 109 yr.)

Alpha particles are identical to

The dose unit of ionizing radiation is called the rad. The rad is defined in terms of

List the number of protons, neutrons, and nucleons (protons + neutrons) , in that order, for an isotope with the symbol: 56137^{137}_{~~56} 56137​ Ba

Both H2O and D2O can be used as moderators to slow neutrons in nuclear reactors.

What fraction of radioactive atoms remains in a sample after six half-lives

The only stable isotope of aluminum is aluminum-27. What type of radioactive decay should be expected from 1328Al{ }_{13}^{28} \mathrm{Al}1328​Al

Complete and balance the nuclear equation 01n+92235U→3587Br+301n+{ }_{0}^{1} \mathrm{n}+{ }_{92}^{235} \mathrm{U} \rightarrow{ }_{35}^{87} \mathrm{Br}+3{ }_{0}^{1} \mathrm{n}+01​n+92235​U→3587​Br+301​n+ _______

The type of nuclear process illustrated below is called electron capture. 62138Sm+−10β⟶61138Pm{ }_{62}^{138} \mathrm{Sm}+{ }_{-1}^{0} \beta \longrightarrow{ }_{61}^{138} \mathrm{Pm}62138​Sm+−10​β⟶61138​Pm

Radioactive nitrogen-13 has a half-life of 10 minutes. After 40 minutes, how much of this isotope would remain in a sample that originally contained 96 mg

Sodium-22 is more stable than sodium-23.

Determine how much energy is released when thorium-230 decays according to 230Th→4He+226Ra{ }^{230} \mathrm{Th} \rightarrow{ }^{4} \mathrm{He}+{ }^{226} \mathrm{Ra}230Th→4He+226Ra . [Atomic masses: thorium-230 = 230.033127 amu; helium-4 = 4.002603 amu; radium-226 = 226.025403 amu]

On a neutron number versus proton number plot, the nucleus of oxygen-15 lies below the belt of stability. In the radioactive decay of oxygen -15, what subatomic particle is emitted

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed ${ }_{2}^{4} \mathrm{He}+{ }_{4}^{9} \mathrm{Be} \rightarrow{ }_{0}^{1} \mathrm{n}+\_\_\_\_\_\_$

When lead-209 undergoes beta decay the balanced nuclear equation for this reaction is: ${ }_{82}^{209} \mathrm{~Pb} \rightarrow{ }_{83}^{209} \mathrm{Bi}+{ }_{-1}^{0} \beta$

A rock contains 0.37 mg of Pb-206 and 0.95 mg of U-238. Approximately how many U-238 atoms were in the rock when it was formed billions of years ago (The half life for ²³⁸U $\rarr$ ²⁰⁶Pb is 4.5 * 10⁹ yr.)

List the number of protons, neutrons, and nucleons (protons + neutrons) , in that order, for an isotope with the symbol: $^{137}_{~~56}$ Ba

Both H₂O and D₂O can be used as moderators to slow neutrons in nuclear reactors.

The only stable isotope of aluminum is aluminum-27. What type of radioactive decay should be expected from ${ }_{13}^{28} \mathrm{Al}$

Complete and balance the nuclear equation ${ }_{0}^{1} \mathrm{n}+{ }_{92}^{235} \mathrm{U} \rightarrow{ }_{35}^{87} \mathrm{Br}+3{ }_{0}^{1} \mathrm{n}+$ _______

The type of nuclear process illustrated below is called electron capture. ${ }_{62}^{138} \mathrm{Sm}+{ }_{-1}^{0} \beta \longrightarrow{ }_{61}^{138} \mathrm{Pm}$

Determine how much energy is released when thorium-230 decays according to ${ }^{230} \mathrm{Th} \rightarrow{ }^{4} \mathrm{He}+{ }^{226} \mathrm{Ra}$ . [Atomic masses: thorium-230 = 230.033127 amu; helium-4 = 4.002603 amu; radium-226 = 226.025403 amu]