Fission, fusion and how radiation is used

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   A neutron strikes uranium with mass number 235. It splits into xenon with mass number 140, strontium with mass number 94, and some neutrons. How many neutrons, Bo?

   2 neutrons
2. 2.

   A neutron strikes uranium with mass number 235. It splits into barium with mass number 144, krypton with mass number 89, and some neutrons. How many neutrons, Esme?

   3 neutrons

3. Read this first

   Nuclear notation: a splitting and a joining (OpenStax §21.4)

   process	equation	where it happens
   fission (splitting)	uranium-235 + neutron → barium-141 + krypton-92 + 3 neutrons	nuclear power plants
   fusion (joining)	4 hydrogen-1 → helium-4 + 2 positrons	the Sun's core

4. 3.

   Using the card, which process splits a heavy nucleus, Jun?

   • Combustion
   • Fusion
   • Fission
5. 4.

   Using the card, which process powers the Sun, Kira?

   • Fusion
   • Burning coal
   • Fission
6. 5.

   Using the card, what does the Sun's fusion make from hydrogen, Luz?

   • Uranium
   • Carbon dioxide
   • Helium
7. 6.

   What do nuclear power plants use to make heat, Milo?

   • Fission of uranium-235
   • Fusion of hydrogen into helium
   • Burning of coal
8. 7.

   What are medical tracers such as technetium-99m used for, Noah?

   • Showing organs in scans
   • Dating old bones
   • Powering the hospital lights
9. 8.

   What is carbon-14 used for, Pia?

   • Making electricity in power plants
   • Lighting the Sun
   • Dating once-living things
10. 9.

    In a nuclear power plant, what does the heat from fission do, Ren?

    • Boils water into steam for turbines
    • Lights the bulbs in our homes directly
    • Turns into uranium again
11. 10.

    Why does fission keep going as a chain reaction, Zee?

    • Steam splits the nuclei
    • Uranium pulls in heat from the steam
    • Each fission releases neutrons