Plutonium-239 is a radioactive isotope frequently employed as nuclear reactor fuel, with a half- life of 24,100 years. Approximately how much time would be required for 504 grams of plutonium-239 to undergo decay, leaving only 63 grams of plutonium-239 behind? (1 point)

Question

96,400 years

72,300 years

24,100 years

48,200 years

Answer 1

To determine the time required for 504 grams of plutonium-239 to decay down to 63 grams, we can use the concept of half-lives.

The half-life of plutonium-239 is 24,100 years. The amount of plutonium-239 is reduced by half with each half-life.

Starting with 504 grams, let's find out how many half-lives it takes to reduce it to 63 grams:

1. Half-life 1: 504 grams → 252 grams (after 24,100 years)
2. Half-life 2: 252 grams → 126 grams (after 48,200 years)
3. Half-life 3: 126 grams → 63 grams (after 72,300 years)

It takes 3 half-lives to decay from 504 grams to 63 grams.

Now, to find the total time:

3 half-lives × 24,100 years/half-life = 72,300 years

Therefore, the time required for 504 grams of plutonium-239 to decay to 63 grams is 72,300 years.

Answer 2

1001 Physical Science A (MS): Nucicar Processes Unit Test

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1001 Physical Science A (MS)

UNIT 5 Nuclear Processes

LESSON

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Nuclear Processes Unit Test

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What conclusion can be drawn about nuclear power from the information presented in the graph?

(1 point)

Nuclear radiation can be safely disposed of in any location due to its natural decay process.

Waste materials from various energy sources undergo decay, similar to nuclear radiation

Engineers must prioritize the swift disposal of nuclear waste to initiate the decay process promptly

Nuclear radiation can persist in the environment for extended periods because its decay can be a Janntry hene

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Answer 3

Based on the information provided, it appears that you are analyzing a graph related to nuclear processes and decay over time. While I can't view the graph directly, I can help you interpret the options based on general knowledge about nuclear power and waste.

Here's an analysis of the answer choices:

1. "Nuclear radiation can be safely disposed of in any location due to its natural decay process."

   • This statement is misleading. While radioactive materials do decay over time, their disposal requires careful consideration of safety and environmental impact.

2. "Waste materials from various energy sources undergo decay, similar to nuclear radiation."

   • This statement is too broad and not entirely accurate. While some waste from various energy sources may degrade or become less harmful over time, it does not undergo the same type of radioactive decay as nuclear waste.

3. "Engineers must prioritize the swift disposal of nuclear waste to initiate the decay process promptly."

   • While timely disposal is important, the process of decay happens naturally over time regardless of disposal speed, so this statement suggests a misunderstanding of decay.

4. "Nuclear radiation can persist in the environment for extended periods because its decay can be a lengthy process."

   • This is a well-supported statement. Many radioactive isotopes, including those used in nuclear power, have long half-lives, meaning they can be hazardous for extended periods.

Given the context of nuclear waste and its long-term impact, the most logical conclusion based on the decaying nature of nuclear materials would be:

"Nuclear radiation can persist in the environment for extended periods because its decay can be a lengthy process."

This answer highlights the concern about the long-term storage and management of nuclear waste.

Answer 4

The graph displays the spectrum of carbon dioxide (CO2) emissions associated with generating one kilowatt-hour through various electricity production methods.

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Greenhouse Gas Emissions from Electricity Production

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coal- modern plant

natural gas

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biomass

forestry waste combustion

solar photovoltaic

wind

nuclear power

hydropower

How does the quantity of carbon dioxide emitted by nuclear power compare to that generated by alternative energy sources?(1 point)

In the graph, nuclear power generates a lower amount of carbon dioxide compared to all other energy sources.

In the graph, nuclear power yields a greater amount of carbon dioxide than any other energy sources.

In the graph, nuclear power ranks as the second-lowest carbon dioxide emitter

Nuclear power results in the second-highest carbon dioxide emissions depicted in the graph.

Answer 5

Based on the context you provided regarding the graph displaying carbon dioxide (CO2) emissions associated with different electricity production methods, here’s an analysis of the answer choices:

1. "In the graph, nuclear power generates a lower amount of carbon dioxide compared to all other energy sources."

   • This statement would be true if nuclear power emissions are at or near the bottom of the graph compared to all other sources.

2. "In the graph, nuclear power yields a greater amount of carbon dioxide than any other energy sources."

   • This statement would be false if nuclear power is shown as producing less CO2 than more polluting sources like coal or natural gas.

3. "In the graph, nuclear power ranks as the second-lowest carbon dioxide emitter."

   • This statement would be true if nuclear power is displayed just above the lowest emitter (likely renewable sources like wind or solar) but below all other fossil fuel sources.

4. "Nuclear power results in the second-highest carbon dioxide emissions depicted in the graph."

   • This statement would be false if the data shows nuclear emissions lower than several other sources.

Based on typical emissions from carbon-intensive sources such as coal and natural gas, nuclear power generally emits significantly less CO2 than these sources and competes closely with renewable energies too.

If nuclear power is indeed shown to have some level of emissions, but it is lower than all fossil fuels and probably ranks among the lowest emissions sources:

The most accurate conclusion is likely: "In the graph, nuclear power generates a lower amount of carbon dioxide compared to all other energy sources."

If specifically, nuclear is the second lowest after renewables, then "In the graph, nuclear power ranks as the second-lowest carbon dioxide emitter." would be accurate as well. You’ll need to reference the specific position of nuclear power in the graph you've mentioned to finalize the correct option.

Answer 6

A characteristic feature of radioactive isotopes is their unique half-life, representing the duration required for half of the isotope to decay. The table presents the half-lives of four isotopes.

Isotope

carbon-14

Half-Life (Years)

5.7 x 10

potassium-40 radon-222

1.3 x 10° 1.0 x 10

tharium-232

1,4 x 100

Using this data, which isotope would scientists avoid using for dating a fossil?-

(1 point)

thonum-232

Oradon-222

carbon-14

potassium-40

Answer 7

When considering which isotope scientists would avoid using for dating fossils, we need to think about the half-life of each isotope.

1. Carbon-14: Half-life of \(5.7 \times 10^3\) years (approximately 5,700 years). This is commonly used for dating organic materials (fossils) that are up to about 50,000 years old.

2. Potassium-40: Half-life of \(1.3 \times 10^9\) years (approximately 1.3 billion years). This isotope is useful for dating geological samples and is too long for dating most fossils directly.

3. Radon-222: Half-life of \(1.0 \times 10^2\) years (approximately 220 years). This is also not ideal for dating fossils because it is a gas and doesn't remain in solid material for a long time.

4. Thorium-232: Half-life of \(1.4 \times 10^{10}\) years (approximately 14 billion years). This isotope is also too long to be useful for dating fossils.

Given this information, scientists would likely avoid using Radon-222 or Thorium-232 for dating fossils due to their half-lives and the nature of Radon being a gas. However, since Radon-222 has a significantly shorter half-life than Thorium-232, it would still not be practical for fossil dating.

Ultimately, scientists would avoid using Radon-222 for dating fossils. It's considered not suitable due to its gaseous state and relatively short half-life compared to the ideal conditions for dating.

Thus, the answer is:

Radon-222