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.

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

   234
2. 2.

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

   222

3. 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).

4. 3.

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

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

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

   • The mass number
   • Only the nucleus's energy
   • The number of protons inside
6. 5.

   What is an alpha particle made of, Milo?

   • Pure light
   • One electron and one proton
   • 2 protons and 2 neutrons
7. 6.

   What is a beta particle, Noah?

   • A neutron
   • A helium nucleus
   • A fast electron
8. 7.

   What is gamma radiation, Pia?

   • A heavy charged particle
   • High-energy light
   • A proton
9. 8.

   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
10. 9.

    What changes in a chemical change, Tala?

    • The number of protons
    • The mass numbers
    • Bonds and electrons
11. 10.

    Which of these is a nuclear change, Zee?

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