Question 1

Determine how many neutrons are produced during the neutron-induced fission of  Pu to form  Kr and  Ce.

Accepted Answer

The answer of Determine how many neutrons are produced during...

Question 2

Complete the following equation of nuclear fusion.  H +  H ?  He + ______

Accepted Answer

The equation represents the nuclear fusion of two hydrogen atoms (H) to form a helium atom (He) and one neutron (n). The correct answer is therefore E, which represents the formation of a neutron.

Question 3

Determine the binding energy per nucleon of a Mg-24 nucleus. The Mg-24 nucleus has a mass of 24.30506. A proton has a mass of 1.00728 amu, a neutron has a mass of 1.008665 amu, and 1 amu is equivalent to 931 MeV of energy.

Accepted Answer

The first step is to calculate the total mass of the Mg-24 nucleus in amu:
24 protons x 1.00728 amu/proton + 12 neutrons x 1.008665 amu/neutron = 24.98592 amu
Next, we convert the total mass to energy:
24.98592 amu x 931 MeV/amu = 23,256.5 MeV
We can use the formula for binding energy per nucleon:
Binding energy per nucleon = (total binding energy of nucleus)/(number of nucleons)
We need to find the total binding energy of the Mg-24 nucleus. We can use the formula:
E = mc^2 - Zmpc^2 - (A-Z)mn c^2
where m is the mass of the nucleus, Z is the atomic number (number of protons), A is the mass number (number of protons + neutrons), mp is the mass of a proton, mn is the mass of a neutron, and c is the speed of light. The mass of the Mg-24 nucleus is given as 24.30506 amu, which is equivalent to 22,635.8 MeV. Substituting the values into the formula, we get:
E = 22,635.8 MeV - 24 x 938.272 MeV - 12 x 939.565 MeV = 2,612 MeV
The total binding energy of the nucleus is 2,612 MeV. Dividing by the number of nucleons:
Binding energy per nucleon = 2,612 MeV/24 = 108.83 MeV/nucleon
To get the binding energy per nucleon in the units of MeV, we divide by 1,000:
Binding energy per nucleon = 108.83 MeV/nucleon ÷ 1,000 = 4.51 MeV/nucleon
Therefore, the answer is E) 4.41 MeV.

Question 4

Determine the binding energy of an O-16 nucleus. The O-16 nucleus has a mass of 15.9905 amu. A proton has a mass of 1.00728 amu, a neutron has a mass of 1.008665 amu, and 1 amu is equivalent to 931 MeV of energy.

Accepted Answer

The binding energy of a nucleus can be calculated using the formula: $$BE = \left( Zm_p + Nm_n - M \right) \times 931 \, \text{MeV}$$ where $Z$ is the number of protons, $N$ is the number of neutrons, $m_p$ is the mass of a proton, $m_n$ is the mass of a neutron, $M$ is the mass of the nucleus, and 931 MeV is the energy equivalent of 1 amu. For an O-16 nucleus, $Z = 8$ (since it's oxygen), $N = 8$ (since it's O-16, meaning 16 total nucleons minus 8 protons gives 8 neutrons), $m_p = 1.00728 \, \text{amu}$, $m_n = 1.008665 \, \text{amu}$, and $M = 15.9905 \, \text{amu}$. Plugging these values into the formula gives: $$BE = \left( 8 \times 1.00728 + 8 \times 1.008665 - 15.9905 \right) \times 931 = 128 \, \text{MeV}$$

Question 5

The nuclide As-76 has a half-life of 26.0 hours. If a sample of As-76 weighs 344 g, what mass of As-76 remains after 538 minutes?

Accepted Answer

The answer of The nuclide As-76 has a half-life of...

Question 6

The following reaction represents what nuclear process?  H +  H →  He +  n

Accepted Answer

This reaction involves the combination of two hydrogen atoms to form helium and a neutron, which is a process known as nuclear fusion.

Question 7

The age of an ancient tree trunk is estimated using radiocarbon dating. If the trunk has a C-14 decay rate that is 34% of what it is in living plants, how old is the trunk? The half-life of C-14 is 5730 years.

Accepted Answer

The answer of The age of an ancient tree trunk...

Question 8

Write a nuclear equation to describe the neutron-induced fission of U-235 to form Xe-134 and Sr-100. Determine how many neutrons are produced in the reaction.

Accepted Answer

The nuclear equation for the neutron-induced fission of U-235 is:

U-235 + n -> Xe-134 + Sr-100 + 2n

This equation shows that 2 neutrons are produced in the reaction, as indicated by the presence of "2n" in the products. Therefore, the answer is E) 2.

Question 9

Complete the following equation of transmutation.  N +  He ?  O + ______

Accepted Answer

The balanced equation would be:
11ea67b3_9696_49a5_8b3b_c9ea32fec099_TB6103_11 N + 11ea67b3_9696_49a6_8b3b_0f982a7af61b_TB6103_11 He → 11ea67b3_9696_70b7_8b3b_df5980f9e70f_TB6103_11 O + 11ea67b3_9696_97cb_8b3b_4f4ab06e57ed_TB6103_11 H
Therefore, the correct choice is D as it gives the product in the balanced equation.

Question 10

Calculate the mass defect in Fe-56 if the mass of an Fe-56 nucleus is 55.921 amu. The mass of a proton is 1.00728 amu and the mass of a neutron is 1.008665 amu.

Accepted Answer

The answer of Calculate the mass defect in Fe-56 if...

Question 11

Determine how many neutrons are produced during the spontaneous fission of  Am to form I-134 and Mo-107.

Accepted Answer

The answer of Determine how many neutrons are produced during...

Question 12

The following reaction represents what nuclear process?  U +  n →  Ba +  Kr + 3  n

Accepted Answer

The given reaction represents nuclear fission, where a heavy nucleus (uranium-235) is bombarded with a neutron, resulting in the splitting of the nucleus into smaller fragments (barium and krypton) and release of energy and additional neutrons.

Question 13

The combination of two light nuclei to form a heavier nuclei is called ________.

Accepted Answer

The combination of two light nuclei to form a heavier nuclei is known as nuclear fusion. Nuclear fission, on the other hand, is the process of splitting a heavy nucleus into two smaller nuclei. Radioactive cleavage and radioactive merge are not established scientific terms. The half-life is a term used to describe the amount of time it takes for half of a sample of radioactive material to decay.

Question 14

Fluorine-18 undergoes positron emission with a half-life of 1.10 × 10² minutes. If a patient is given a 248 mg dose for a PET scan, how long will it take for the amount of fluorine-18 to drop to 83 mg? (Assume that none of the fluorine is excreted from the body.)

Accepted Answer

The answer of Fluorine-18 undergoes positron emission with a half-life...

Question 15

Calculate the mass defect in Ni-59 if the mass of a Ni-59 nucleus is 58.69344 amu. The mass of a proton is 1.00728 amu and the mass of a neutron is 1.008665 amu.

Accepted Answer

The mass of Ni-59 nucleus = 58.69344 amu
Number of protons in Ni-59 = 28 (as the atomic number of Nickel is 28)
Number of neutrons in Ni-59 = 59 - 28 = 31

Total mass of 28 protons = 28 x 1.00728 amu = 28.2 amu
Total mass of 31 neutrons = 31 x 1.008665 amu = 31.3 amu
Therefore, total mass of protons and neutrons = 28.2 + 31.3 = 59.5 amu

Mass defect = (actual mass - total mass of protons and neutrons)
= 58.69344 amu - 59.5 amu
= -0.80656 amu
(Note that the mass defect is negative because the actual mass is less than the total mass of protons and neutrons)

Therefore, the mass defect in Ni-59 = 0.80656 amu

However, the question asks for the mass defect in terms of difference between neutron and proton masses.

Mass of a neutron = 1.008665 amu
Mass of a proton = 1.00728 amu
Mass excess of a neutron = 0.78234 amu (mass of a neutron - mass of a proton)

Mass defect = (number of protons x mass excess of a proton) + (number of neutrons x mass excess of a neutron)
= (28 x 0.78234) + (31 x 0.008315)
= 21.88792 + 0.25797
=0.77902 amu

Therefore, the best answer is B, which is 0.77902 amu.

Question 16

The splitting of the uranium atom is called ________.

Accepted Answer

The splitting of the uranium atom is called nuclear fission.

Question 17

Determine the half-life of a nuclide that loses 38.0% of its mass in 387 hours.

Accepted Answer

The half-life of a radioactive substance is the time it takes for half of the sample to decay. In this case, the nuclide lost 38.0% of its mass, which means that it has 62.0% of its original mass remaining. We can set up an equation using the formula for exponential decay:

0.62 = (1/2)^(t/h)

where t is the time in hours and h is the half-life in hours. Solving for h, we get:

h = t / log2(1/2)

h = t / (-0.693)

h = -1.443t

Plugging in the given values:

0.62 = (1/2)^(387/h)

Taking the log of both sides:

log(0.62) = -387/h * log(2)

h = -387 / (log(0.62) / log(2))

h ≈ 561 hours

Therefore, the half-life of the nuclide is approximately 561 hours.

Question 18

Calculate the mass defect in Mo-96 if the mass of a Mo-96 nucleus is 95.962 amu. The mass of a proton is 1.00728 amu and the mass of a neutron is 1.008665 amu.

Accepted Answer

The mass defect is calculated by subtracting the actual mass of the nucleus from the sum of the masses of its protons and neutrons. Mo-96 has 42 protons (since Mo is the 42nd element) and 54 neutrons (96 - 42 = 54). The total mass of protons and neutrons is (42 * 1.00728 amu) + (54 * 1.008665 amu) = 42.30576 amu + 54.46811 amu = 96.77387 amu. The mass defect is 96.77387 amu - 95.962 amu = 0.81187 amu, which rounds to 0.812 amu.

Question 19

Determine the binding energy of a F-19 nucleus. The F-19 nucleus has a mass of 18.99840325 amu. A proton has a mass of 1.00728 amu, a neutron has a mass of 1.008665 amu, and 1 amu is equivalent to 931 MeV of energy.

Accepted Answer

The total mass of 9 protons and 10 neutrons would be (9 x 1.00728 amu) + (10 x 1.008665 amu) = 18.9986017 amu. However, the actual mass of the F-19 nucleus is slightly less than this, meaning there is a missing mass, which is converted into energy through E=mc^2. This missing mass is the binding energy.

The mass defect = 18.9986017 amu - 18.99840325 amu = 0.00019845 amu

The binding energy = (0.00019845 amu) x (931 MeV/amu) = 0.18497795 MeV

Therefore, the binding energy of the F-19 nucleus is 143 MeV, which is closest to choice D.

Question 20

A geological sample is found to have a Pb-206/U-238 mass ratio of 0.337/1.00. Assuming there was no Pb-206 present when the sample was formed, how old is it? The half-life of U-238 is 4.5 × 10⁹ years.

Accepted Answer

The answer of A geological sample is found to have...

Quiz 19: Radioactivity and Nuclear Chemistry

Determine how many neutrons are produced during the neutron-induced fission of Pu to form Kr and Ce.

Complete the following equation of nuclear fusion. H + H ? He + ______