Worksheet

Mass and energy: E = mc²

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. A power plant sends out 1000 MW of electrical power for 365 days. With c = 2.99792458 × 10⁸ m/s, how much mass equals that energy, to 0.01 g, Bo?

  2. A power plant sends out 500 MW of electrical power for 30 days. With c = 2.99792458 × 10⁸ m/s, how much mass equals that energy, to 0.01 g, Esme?

  3. Read this first

    Photon diagram for a nucleus splitting

    One neutron hits one uranium-235 nucleus, which splits into barium-141, krypton-92 and three neutrons. Total mass before: 236.052595 u. Total mass after: 235.866571 u.

  4. In the photon diagram, how many neutrons come out for the one that went in, Jun?

    • Just one
    • Three
    • Two

  5. In the photon diagram, why can the freed neutrons keep a reactor running, Kira?

    • They can split more uranium-235
    • They add mass to the fuel
    • They turn back into uranium

  6. Milo says fusion and fission make energy from nothing. Agree or disagree?

    • Agree: E = mc² adds extra energy
    • Disagree: lost mass becomes the energy
    • Agree: nuclei create brand-new energy

  7. Noah says a reactor turns its whole fuel mass into energy. Agree or disagree?

    • Agree: E = mc² uses the whole mass
    • Disagree: under 1% of the mass does
    • Agree: the used fuel has no mass left

  8. Pia says 1 kg of fusion fuel releases 1 kg × c² of energy. Agree or disagree?

    • Disagree: only about 0.4% of it changes
    • Agree: the fuel vanishes as energy
    • Agree: E = mc² uses the whole kilogram

  9. Why does one fusion reaction release millions of times more energy than burning one molecule, Ren?

    • Fusion uses heavier atoms
    • Nuclear forces beat chemical bonds
    • Burning loses most of its energy as smoke

  10. Per kilogram of fuel, which gives more energy: D–T fusion or uranium-235 fission, Tala?

    • Fusion, by about 4 to 5 times
    • Fission, by about 10 times or more
    • Both give the same amount

  11. Why can the Sun keep shining for billions of years more, Zee?

    • Its fusion uses its whole mass at once
    • It has vast hydrogen to fuse
    • Its whole mass turns to light each year
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Mass and energy: E = mc²

Answer Key - Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

  1. A power plant sends out 1000 MW of electrical power for 365 days. With c = 2.99792458 × 10⁸ m/s, how much mass equals that energy, to 0.01 g, Bo?

    350.89 g

  2. A power plant sends out 500 MW of electrical power for 30 days. With c = 2.99792458 × 10⁸ m/s, how much mass equals that energy, to 0.01 g, Esme?

    14.42 g

  3. Read this first

    Photon diagram for a nucleus splitting

    One neutron hits one uranium-235 nucleus, which splits into barium-141, krypton-92 and three neutrons. Total mass before: 236.052595 u. Total mass after: 235.866571 u.

  4. In the photon diagram, how many neutrons come out for the one that went in, Jun?

    • Just one
    • Three
    • Two

  5. In the photon diagram, why can the freed neutrons keep a reactor running, Kira?

    • They can split more uranium-235
    • They add mass to the fuel
    • They turn back into uranium

  6. Milo says fusion and fission make energy from nothing. Agree or disagree?

    • Agree: E = mc² adds extra energy
    • Disagree: lost mass becomes the energy
    • Agree: nuclei create brand-new energy

  7. Noah says a reactor turns its whole fuel mass into energy. Agree or disagree?

    • Agree: E = mc² uses the whole mass
    • Disagree: under 1% of the mass does
    • Agree: the used fuel has no mass left

  8. Pia says 1 kg of fusion fuel releases 1 kg × c² of energy. Agree or disagree?

    • Disagree: only about 0.4% of it changes
    • Agree: the fuel vanishes as energy
    • Agree: E = mc² uses the whole kilogram

  9. Why does one fusion reaction release millions of times more energy than burning one molecule, Ren?

    • Fusion uses heavier atoms
    • Nuclear forces beat chemical bonds
    • Burning loses most of its energy as smoke

  10. Per kilogram of fuel, which gives more energy: D–T fusion or uranium-235 fission, Tala?

    • Fusion, by about 4 to 5 times
    • Fission, by about 10 times or more
    • Both give the same amount

  11. Why can the Sun keep shining for billions of years more, Zee?

    • Its fusion uses its whole mass at once
    • It has vast hydrogen to fuse
    • Its whole mass turns to light each year