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9th grade · Science · Unit 27 of 28

Nuclear Energy & Bond Energy

Fission, fusion and decay, and the energy in chemical bonds.

What your child practices

Practices how nuclei change in fission, fusion and radioactive decay, what alpha, beta and gamma radiation are, half-life calculations, and how the energy absorbed to break bonds and released to form bonds makes a reaction give off or take in energy.

New York State Learning Standards learning standard: HS-PS1-8; HS-PS1-4 · changes in the nucleus during fission, fusion and radioactive decay, and how breaking and forming bonds releases or absorbs energy

How we explain it

Children can open this short lesson before they practice.

  1. Fission splits big nuclei; fusion joins small ones. Both release energy.
  2. Alpha is stopped by paper, beta by thin metal; gamma is high-energy radiation that needs thick lead or concrete.
  3. A half-life is the time for half the radioactive atoms to decay.

Example: An 80 g sample has a half-life of 5 days. How much is left after 10 days? 10 days is 2 half-lives. 80 → 40 → 20. Answer: 20 g

Nuclear Energy & Bond Energy in New York

In the New York State Learning Standards, this is unit 27 of 28 in 9th grade Science, after Gases, Solutions, Acids & Bases and before Forces at a Distance & Heat Flow.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: New York State Education Department (NYSED)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A beta particle is…

    • a fast-moving electron
    • a photon of visible light
    • a helium nucleus
    • a pair of neutrons

  2. Question 2

    Forming a chemical bond…

    • releases energy
    • needs no energy
    • destroys atoms
    • absorbs energy

  3. Question 3

    In alpha decay, the atomic number of the nucleus…

    • drops by 2
    • drops by 4
    • stays the same
    • rises by 2

  4. Question 4

    In nuclear reactions, the total number of protons and neutrons…

    • stays the same
    • drops to zero
    • changes at random
    • always doubles

  5. Question 5

    Nuclear power plants make electricity using…

    • fusion of hydrogen
    • fission of uranium
    • burning oil
    • solar panels

  6. Question 6

    Uranium-238 (92 protons) gives off an alpha particle. How many protons does the new nucleus have?

    • 92
    • 94
    • 88
    • 90

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