SPS4. Nuclear Chemistry

What are the changes in nuclear structure as a result of fission and fusion?

• The nucleus becomes larger in fission and smaller in fusion.

• The nucleus becomes smaller in fission and larger in fusion.

• The nucleus remains the same size in both fission and fusion.

• The nucleus becomes unstable in fission and stable in fusion.

Tags

SPS4a

Which process involves the splitting of a nucleus into two smaller nuclei?

• Fusion

• Radioactive decay

• Half-life

• Fission

Tags

SPS4a

Uranium is bombarded by a neutron to start the process of fission as shown by the nuclear equation.

What is needed to complete the equation?

•  3 neutrons

• 3 beta particles

• 3 alpha particles

• 3 hydrogen atoms

Tags

SPS4a

The diagram shows 2 hydrogen isotopes combining and producing helium and a neutron. What process is respresented by the diagram?

• alpha decay

• beta decay

• fission

• fusion

Tags

NGSS.HS-PS1-8

What is the time it takes for half of a radioactive substance to decay called?

• Radioactive period

• Half-life

• Decay time

• Nuclear breakdown

Tags

SPS4b

Uranium-238, the most prevalent isotope in uranium ore, has a half-life of 4.5 billion years and spontaneously decays by alpha emission to thorium-234. If a sample of uranium ore contains 1,000 grams of uranium-238, how long will it take for 875 grams to decay to thorium-234? (875 grams is how much that has been lost/decayed. So 1000-875 = ? Based on that, how many half lives have taken place)

• 4.5 billion years

• 9.0 billion years 

• 13.5 billion years 

• 18.0 billion years

Tags

SPS4b

Why are scientists currently researching how to develop nuclear fusion power as a clean energy source for the future? What are the challenges they are facing?

• The materials produced in a nuclear fusion reactor are not hazardous.

  Challenge: Fusion requires extrem temperature and pressure.

• A nuclear fusion reactor does not need a containment vessel for the fusion reactions. 

  Challenge: Where to store radioactive wastes.

• A nuclear fusion reactor boils water to produce steam which will be used to generate electricity.  

  Challenge: evironmental concerns

• A nuclear fusion reactor must be heated to about 100,000,000 °C for the fuel to reach a plasma state. 

  Challenge: Thermal pollution in water sources.

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SPS4c

What are the benefits of nuclear energy as an alternative energy source?

• Nuclear energy has a high energy output and reduces greenhouse gas emissions.

• Nuclear energy produces no waste and is completely safe.

• Nuclear energy is cheap and readily available.

• Nuclear energy is renewable and has no negative impact on the environment.

Tags

SPS4c

If the half-life of iodine-131 is 8 days, how much of a 5.0g sample is left after 32 days?

• 2.5g

• 1.25g

• 0.625g

• 0.3125g

Tags

SPS4b

Potassium-40 has a half-life of 1.28 billion years. What is the age of a rock in which 87.5% of the potassium-40 atoms have decayed to argon-40?

• 1.28 billion years

• 2.56 billion years

• 3.84 billion years

• 7.68 billion years

Tags

NGSS.HS-PS1-8