Fission, fusion and how radiation is used

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   Fission of uranium-235 gives about 2500000 times the energy of the same mass of coal. How many kilograms of coal match 2 kg of uranium-235, Ari?

   5,000,000 kg
2. 2.

   Fission of uranium-235 gives about 2500000 times the energy of the same mass of coal. How many kilograms of coal match 3 kg of uranium-235, Esme?

   7,500,000 kg
3. 3.

   In 4 hydrogen-1 → helium-4 + 2 positrons, why are two positrons given off, Jun?

   • To balance the mass: 4 = 2 + 2
   • To balance the charge: 4 = 2 + 2
   • To make the helium nucleus much heavier
4. 4.

   What is the Sun's main nuclear fuel, Kira?

   • Hydrogen
   • Uranium
   • Coal
5. 5.

   What charge does a positron carry, Luz?

   • +1
   • 0
   • −1
6. 6.

   Milo says the Sun shines by splitting heavy atoms. Agree or disagree?

   • Disagree: it fuses hydrogen into helium
   • Agree: the Sun splits heavy atoms like a reactor
   • Agree: the Sun burns coal
7. 7.

   Noah says nuclear power plants make energy by joining hydrogen nuclei. Agree or disagree?

   • Disagree: they split uranium-235
   • Agree: plants burn hydrogen gas
   • Agree: plants join light nuclei like the Sun
8. 8.

   Pia says a nuclear power plant burns uranium the way a stove burns gas. Agree or disagree?

   • Agree: both make carbon dioxide
   • Agree: uranium reacts with oxygen as it burns
   • Disagree: fission is a nuclear change
9. 9.

   Which isotope or process fits dating a wooden bowl, Ren?

   • Uranium-235 fission
   • Carbon-14
   • Hydrogen fusion
10. 10.

    Which isotope fits a short-lived tracer for medical scans, Tala?

    • Uranium-235
    • Carbon-14
    • Technetium-99m