Alpha, beta and gamma decay

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   Polonium with mass number 210 gives off an alpha particle. What is the new mass number, Ari?

   206
2. 2.

   Uranium with mass number 238 gives off an alpha particle. What is the new mass number, Bo?

   234
3. 3.

   Radium with mass number 226 gives off an alpha particle. What is the new mass number, Esme?

   222

4. Read this first

   Nuclear notation

   Before and after (OpenStax §21.3). Columns: decay, before, given off, after. alpha, polonium-210 (84 protons), helium-4 nucleus (2 protons), lead-206 (82 protons); beta, iodine-131 (53 protons), electron (charge −1), xenon-131 (54 protons); gamma, excited cobalt-60 (27 protons), gamma ray (no mass, no charge), cobalt-60 (27 protons).

5. 4.

   Using the card, what does alpha decay give off, Jun?

   • A gamma ray of light
   • An electron from the shell
   • A helium-4 nucleus
6. 5.

   Using the card, what happens to the mass number in beta decay, Kira?

   • It stays the same
   • It drops by 4 each time
   • It rises by 1
7. 6.

   Using the card, what does gamma decay change, Luz?

   • The number of protons inside
   • The mass number
   • Only the nucleus's energy
8. 7.

   What is an alpha particle made of, Milo?

   • 2 protons and 2 neutrons
   • One electron and one proton
   • Pure light
9. 8.

   What is gamma radiation, Pia?

   • A heavy charged particle
   • High-energy light
   • A proton
10. 9.

    What changes in a nuclear change, Ren?

    • The color and the smell of the substance
    • The nucleus, so the element can change
    • The bonds that link separate atoms
11. 10.

    Which of these is a nuclear change, Zee?

    • Iron rusting in damp air
    • Methane burning in a stove
    • Carbon-14 becoming nitrogen-14