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?

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

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

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

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

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

   What is an alpha particle made of, Milo?

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

   What is a beta particle, Noah?

   • A neutron
   • A fast electron
   • A helium nucleus
10. 9.

    What is gamma radiation, Pia?

    • A heavy charged particle
    • High-energy light
    • A proton
11. 10.

    What changes in a nuclear change, Ren?

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