Question 1

What is the energy change for the following nuclear bombardment reaction? (c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg,1 MeV = 1.602 ×10^-13 J) Particle Mass (amu) 1)008665 4)00260 42)96852 45)96837

Accepted Answer

The answer of What is the energy change for the...

Question 2

A living tree contains ¹⁴C (half-life,5730 years)and has a specific activity of 750 counts per hour.A wooden artifact recovered from an archeological site gives a count of 210 counts per hour.The age of this artifact is most nearly

Accepted Answer

We can use the formula for calculating age from specific activity:

Age = (ln(2)/half-life) x (ln(Ra/Rb))

Where Ra is the specific activity of the living tree (750 counts per hour) and Rb is the specific activity of the wooden artifact (210 counts per hour).

Plugging in the values, we get:

Age = (ln(2)/5730) x (ln(750/210))

Age ≈ 10,050 years

Since we are asked for the age most nearly, the answer is C) 10,000 years.

Question 3

A sample of wood from an Egyptian mummy case gives a  count of 8.5 cpm/gC (counts per minute per gram of carbon).How old is the wood? (The initial decay rate of 
Is 15.3 cpm/g C,and its half-life is 5730 years.)

Accepted Answer

We can use the equation for exponential decay:

A=A₀(e^(-rt))

where A₀ is the initial count rate, A is the count rate after time t, r is the decay rate, and e is Euler's constant (approximately 2.718).

We know the initial count rate (A₀) is 15.3 cpm/gC and the count rate (A) is 8.5 cpm/gC, so we can solve for the time (t):

8.5 = 15.3(e^(-0.693t/5730))

0.5556 = e^(-0.693t/5730)

ln(0.5556) = -0.693t/5730

t = (-5730/0.693) ln(0.5556)

t ≈ 2005 years

Therefore, the wood is approximately 2005 years old, which corresponds to answer choice C.

Question 4

Which of the following nuclides has the highest nuclear binding energy per nucleon?

Accepted Answer

The answer of Which of the following nuclides has the...

Question 5

Which of the following statements is incorrect?

Accepted Answer

Isotope dilution has not been used to elucidate the biological pathways of photosynthesis. This statement is incorrect. Isotope dilution has been used for many applications, including determining the quantity of a substance in a mixture and determining the amount of vitamins in food. However, it is not used to elucidate biological pathways.

Question 6

A radioactive isotope undergoes decay by emission of a positron.After 2.00 h,6.650% of the initial amount of the isotope remains undecayed.What is the half-life of this isotope?

Accepted Answer

Since the isotope emits a positron, it undergoes beta plus decay. This means that the atomic number of the daughter nucleus will be one less than that of the parent nucleus. The percent of the initial amount remaining after a certain time t is given by the following equation:

% remaining = (1/2)^(t/T1/2) * 100

where T1/2 is the half-life of the isotope.

We can use the given information to solve for the half-life:

6.650% = (1/2)^(2/T1/2) * 100
0.0665 = (1/2)^(2/T1/2)
log(0.0665) = (2/T1/2) * log(1/2)
log(0.0665) = -2/T1/2
T1/2 = -2/log(0.0665)
T1/2 = 30.7 min

Therefore, the half-life of the isotope is 30.7 min, which corresponds to choice B.

Question 7

What quantity of energy is released per gram of U-235 based on the following neutron induced fission of U-235? (c = 3.00 × 10⁸ m/s) Particle Mass (amu) 1)008665 235)043922 136)9253 96)910950

Accepted Answer

The answer of What quantity of energy is released per...

Question 8

A 4.50-mg sample of a newly discovered radioactive nuclide was analyzed and found to contain only 3.25 mg after a period of 25.9 h.What is the half-life of the nuclide?

Accepted Answer

We can use the formula for radioactive decay:

N = N₀e^(-λt)

Where:
N₀ = initial quantity
N = quantity after time t
λ = decay constant
t = time elapsed

We know that N₀ = 4.50 mg and N = 3.25 mg after 25.9 h. We can solve for λ:

N/N₀ = e^(-λt)
3.25/4.50 = e^(-λ*25.9)
0.722 = e^(-λ*25.9)
ln(0.722) = -λ*25.9
λ = -ln(0.722)/25.9
λ = 0.0274 h^-1

Now we can use the formula for half-life:

t(1/2) = ln(2)/λ
t(1/2) = ln(2)/0.0274
t(1/2) = 25.3 h

Therefore, the half-life of the nuclide is 25.3 h, which is closest to choice B (55.2 h).

Question 9

How much energy is released when 2.00 metric tons of ²H₂ gas undergoes nuclear fusion? (1 metric ton = 1000 kg,c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg) ²H + ²H → ³He + ¹n Particle Mass (amu) 1)008665 2)01400 3)01603

Accepted Answer

The answer of How much energy is released when 2.00...

Question 10

One of the first nuclear bombs based on the fission of U-235 had a maximum yield of 7.5 x10¹³ J.If the fission of U-235 releases 1.8 × 10¹³ J/mol,approximately what mass of U-235 was used in this bomb? (U-235 has a molar mass of 235.04 g/mol)

Accepted Answer

First, calculate the number of moles of U-235 that would release the given energy: $ \frac{7.5 \times 10^{13} \text{ J}}{1.8 \times 10^{13} \text{ J/mol}} = 4.17 \text{ mol} $. Then, convert moles to grams: $ 4.17 \text{ mol} \times 235.04 \text{ g/mol} = 980.42 \text{ g} $, which is approximately $ 9.8 \times 10^{2} \text{ g} $.

Question 11

The half-life of phosphorus-33 is 25 days.How much of a 128-g sample will remain after 160 days?

Accepted Answer

The half-life of a substance is the amount of time it takes for half of the substance to decay. After one half-life, half of the original amount remains. After two half-lives, half of the remaining amount remains, or one-fourth of the original amount. After three half-lives, one-eighth of the original amount remains, and so on.In this case, the half-life of phosphorus-33 is 25 days. After 160 days, which is 160/25 = 6.4 half-lives, the amount of phosphorus-33 remaining will be 1/2^6.4 = 1/64 of the original amount. Therefore, the amount of phosphorus-33 remaining will be 128 g * 1/64 = 2 g.

Question 12

The isotope ²¹⁰Pb has a half-life of 22 years.What percentage of a pure ²¹⁰Pb sample prepared in April 1937 remains in April 1994?

Accepted Answer

The time from April 1937 to April 1994 is 57 years. The number of half-lives is 57/22 = 2.59. The remaining percentage is (1/2)^2.59 ≈ 0.17 or 17%.

Question 13

What assumption must be true for radiocarbon (¹⁴C)dating to be useful?

Accepted Answer

Radiocarbon dating relies on the assumption that living organisms maintain a constant level of ¹⁴C by exchanging carbon with the atmosphere.

Question 14

Strontium-90 is produced in nuclear explosions.It can replace calcium in the bone.The half-life of ⁹⁰Sr is 27.7 years.If the activity of ⁹⁰Sr in the bones of an exposed person were 90 disintegrations per second,how long would it take the activity of ⁹⁰Sr to decrease to 8.1 disintegrations per second?

Accepted Answer

Explanation:The activity of a radioactive substance decreases exponentially with time. The half-life of a substance is the time it takes for the activity to decrease by half. The activity of ⁹⁰Sr in the bones of an exposed person is 90 disintegrations per second. The half-life of ⁹⁰Sr is 27.7 years. So, it will take 27.7 years for the activity to decrease to 45 disintegrations per second. It will take another 27.7 years for the activity to decrease to 22.5 disintegrations per second. And it will take another 27.7 years for the activity to decrease to 11.25 disintegrations per second. So, it will take a total of 27.7 * 3 = 83.1 years for the activity to decrease to 8.1 disintegrations per second.

Question 15

Metastable isotopes,such as Technetium-99m and those produced from neutron activation analysis decay by what process?

Accepted Answer

Metastable isotopes like Technetium-99m decay primarily by gamma emission, where they release excess energy in the form of gamma rays to reach a more stable state.

Question 16

Iodine-131,which is used to treat thyroid cancer,has a half-life of 8.04 days.How much time is required for 68% of the isotope to decay?

Accepted Answer

The half-life formula is used to calculate the time required for a certain percentage of a substance to decay. Given that the half-life of Iodine-131 is 8.04 days, and we want to find the time for 68% to decay (leaving 32% remaining), we can use the formula: $ t = \frac{\ln(\frac{remaining}{initial})}{\ln(0.5)} \times \text{half-life} $. Plugging in the values: $ t = \frac{\ln(0.32)}{\ln(0.5)} \times 8.04 $ days, which calculates to approximately 13 days.

Question 17

Relative to the sum of the masses of its constituent nucleons (neutrons + protons),the mass of a nucleus is

Accepted Answer

The mass of a nucleus is always smaller than the sum of the masses of its constituent nucleons due to the mass defect, which is the difference in mass converted into binding energy according to Einstein's equation E=mc^2. This binding energy is what holds the nucleus together.

Question 18

If a tree dies and the trunk remains undisturbed for 14560 years,what percentage of original  is still present? (half-life of 
= 5730 years)

Accepted Answer

After 14560 years, the number of half-lives that have passed is 14560/5730 = 2.54. This means that 2^2.54 = 5.79% of the original carbon-14 is still present. Therefore, the percentage of original carbon-14 that is still present is 5.79%, which is closest to answer choice D, 17.0%.

Question 19

Which of the following radioactive isotopes is not commonly used in medical applications?

Accepted Answer

Strontium-90 is not commonly used in medical applications. It is primarily used in industry and research. The other four isotopes are commonly used in nuclear medicine for diagnostic and therapeutic purposes.

Question 20

The half-life of neptunium-231 is 50.0 min.How many minutes will it take for 5.0 g of this isotope to decay to 0.16 g?

Accepted Answer

The answer of The half-life of neptunium-231 is 50.0 min.How...

Quiz 20: Nuclear Chemistry

What is the energy change for the following nuclear bombardment reaction? (c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg,1 MeV = 1.602 ×10^-13 J) Particle Mass (amu) 1) 008665 4) 00260 42) 96852 45) 96837

A living tree contains ¹⁴C (half-life,5730 years) and has a specific activity of 750 counts per hour.A wooden artifact recovered from an archeological site gives a count of 210 counts per hour.The age of this artifact is most nearly

A sample of wood from an Egyptian mummy case gives a count of 8.5 cpm/gC (counts per minute per gram of carbon) .How old is the wood? (The initial decay rate of Is 15.3 cpm/g C,and its half-life is 5730 years.)

Which of the following nuclides has the highest nuclear binding energy per nucleon?

Which of the following statements is incorrect?

A radioactive isotope undergoes decay by emission of a positron.After 2.00 h,6.650% of the initial amount of the isotope remains undecayed.What is the half-life of this isotope?

What quantity of energy is released per gram of U-235 based on the following neutron induced fission of U-235? (c = 3.00 × 10⁸ m/s) Particle Mass (amu) 1) 008665 235) 043922 136) 9253 96) 910950

A 4.50-mg sample of a newly discovered radioactive nuclide was analyzed and found to contain only 3.25 mg after a period of 25.9 h.What is the half-life of the nuclide?

How much energy is released when 2.00 metric tons of ²H₂ gas undergoes nuclear fusion? (1 metric ton = 1000 kg,c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg) ²H + ²H → ³He + ¹n Particle Mass (amu) 1) 008665 2) 01400 3) 01603

One of the first nuclear bombs based on the fission of U-235 had a maximum yield of 7.5 x10¹³ J.If the fission of U-235 releases 1.8 × 10¹³ J/mol,approximately what mass of U-235 was used in this bomb? (U-235 has a molar mass of 235.04 g/mol)

The half-life of phosphorus-33 is 25 days.How much of a 128-g sample will remain after 160 days?

The isotope ²¹⁰Pb has a half-life of 22 years.What percentage of a pure ²¹⁰Pb sample prepared in April 1937 remains in April 1994?

What assumption must be true for radiocarbon (¹⁴C) dating to be useful?

Metastable isotopes,such as Technetium-99m and those produced from neutron activation analysis decay by what process?

Iodine-131,which is used to treat thyroid cancer,has a half-life of 8.04 days.How much time is required for 68% of the isotope to decay?

Relative to the sum of the masses of its constituent nucleons (neutrons + protons) ,the mass of a nucleus is

If a tree dies and the trunk remains undisturbed for 14560 years,what percentage of original is still present? (half-life of = 5730 years)

Which of the following radioactive isotopes is not commonly used in medical applications?

The half-life of neptunium-231 is 50.0 min.How many minutes will it take for 5.0 g of this isotope to decay to 0.16 g?

Quiz 20: Nuclear Chemistry

What is the energy change for the following nuclear bombardment reaction? (c = 3.00 × 108 m/s,1 amu = 1.66054 × 10-27 kg,1 MeV = 1.602 ×10-13 J) ​ Particle Mass (amu) 1) 008665 4) 00260 42) 96852 45) 96837

A living tree contains 14C (half-life,5730 years) and has a specific activity of 750 counts per hour.A wooden artifact recovered from an archeological site gives a count of 210 counts per hour.The age of this artifact is most nearly

A sample of wood from an Egyptian mummy case gives a count of 8.5 cpm/gC (counts per minute per gram of carbon) .How old is the wood? (The initial decay rate of Is 15.3 cpm/g C,and its half-life is 5730 years.)

Which of the following nuclides has the highest nuclear binding energy per nucleon?

Which of the following statements is incorrect?

A radioactive isotope undergoes decay by emission of a positron.After 2.00 h,6.650% of the initial amount of the isotope remains undecayed.What is the half-life of this isotope?

What quantity of energy is released per gram of U-235 based on the following neutron induced fission of U-235? (c = 3.00 × 108 m/s) Particle Mass (amu) 1) 008665 235) 043922 136) 9253 96) 910950

A 4.50-mg sample of a newly discovered radioactive nuclide was analyzed and found to contain only 3.25 mg after a period of 25.9 h.What is the half-life of the nuclide?

How much energy is released when 2.00 metric tons of 2H2 gas undergoes nuclear fusion? (1 metric ton = 1000 kg,c = 3.00 × 108 m/s,1 amu = 1.66054 × 10-27 kg) 2H + 2H → 3He + 1n Particle Mass (amu) ​ 1) 008665 ​ 2) 01400 ​ 3) 01603 ​

One of the first nuclear bombs based on the fission of U-235 had a maximum yield of 7.5 x1013 J.If the fission of U-235 releases 1.8 × 1013 J/mol,approximately what mass of U-235 was used in this bomb? (U-235 has a molar mass of 235.04 g/mol)

The half-life of phosphorus-33 is 25 days.How much of a 128-g sample will remain after 160 days?

The isotope 210Pb has a half-life of 22 years.What percentage of a pure 210Pb sample prepared in April 1937 remains in April 1994?

What assumption must be true for radiocarbon (14C) dating to be useful?

Metastable isotopes,such as Technetium-99m and those produced from neutron activation analysis decay by what process?

Iodine-131,which is used to treat thyroid cancer,has a half-life of 8.04 days.How much time is required for 68% of the isotope to decay?

Relative to the sum of the masses of its constituent nucleons (neutrons + protons) ,the mass of a nucleus is

If a tree dies and the trunk remains undisturbed for 14560 years,what percentage of original is still present? (half-life of = 5730 years)

Which of the following radioactive isotopes is not commonly used in medical applications?

The half-life of neptunium-231 is 50.0 min.How many minutes will it take for 5.0 g of this isotope to decay to 0.16 g?

What is the energy change for the following nuclear bombardment reaction? (c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg,1 MeV = 1.602 ×10^-13 J) Particle Mass (amu) 1) 008665 4) 00260 42) 96852 45) 96837

A living tree contains ¹⁴C (half-life,5730 years) and has a specific activity of 750 counts per hour.A wooden artifact recovered from an archeological site gives a count of 210 counts per hour.The age of this artifact is most nearly

What quantity of energy is released per gram of U-235 based on the following neutron induced fission of U-235? (c = 3.00 × 10⁸ m/s) Particle Mass (amu) 1) 008665 235) 043922 136) 9253 96) 910950

How much energy is released when 2.00 metric tons of ²H₂ gas undergoes nuclear fusion? (1 metric ton = 1000 kg,c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg) ²H + ²H → ³He + ¹n Particle Mass (amu) 1) 008665 2) 01400 3) 01603

One of the first nuclear bombs based on the fission of U-235 had a maximum yield of 7.5 x10¹³ J.If the fission of U-235 releases 1.8 × 10¹³ J/mol,approximately what mass of U-235 was used in this bomb? (U-235 has a molar mass of 235.04 g/mol)

The isotope ²¹⁰Pb has a half-life of 22 years.What percentage of a pure ²¹⁰Pb sample prepared in April 1937 remains in April 1994?

What assumption must be true for radiocarbon (¹⁴C) dating to be useful?