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.

   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 happens to the mass number in beta decay, Kira?

   • It drops by 4 each time
   • It rises by 1
   • It stays the same
5. 4.

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

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

   What is an alpha particle made of, Milo?

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

   What is a beta particle, Noah?

   • A fast electron
   • A neutron
   • A helium nucleus
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 nucleus, so the element can change
   • The color and the smell of the substance
   • The bonds that link separate atoms
10. 9.

    What changes in a chemical change, Tala?

    • Bonds and electrons
    • The number of protons
    • The mass numbers
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