FOCUS ON: Radioactive Decay and Nuclear Radiation

Part 1 - Keywords:

1. Radioactive Decay

2. Nuclear Radiation

3. Unstable Nuclei

4. Activity

5. Becquerel (Bq)

6. Count-rate

7. Alpha Particle (α)

8. Beta Particle (β)

9. Gamma Ray (γ)

10. Neutron (n)

Part 2 - Key Facts:

Radioactive Decay:

• Some atomic nuclei are unstable and undergo radioactive decay to become more stable.

• Radioactive decay is a random process.

Activity and Measurement:

• Activity is the rate at which a source of unstable nuclei decays.

• Activity is measured in becquerel (Bq).

• Count-rate is the number of decays recorded each second by a detector (e.g., Geiger-Muller tube).

Types of Nuclear Radiation:

1. Alpha Particle (α):

   • Consists of two neutrons and two protons.

   • Same as a helium nucleus.

2. Beta Particle (β):

   • High-speed electron ejected as a neutron turns into a proton.

3. Gamma Ray (γ):

   • Electromagnetic radiation from the nucleus.

4. Neutron (n):

   • A neutral subatomic particle emitted in some types of decay.

Part 3 - Quick Quiz:

1. What is the random process by which unstable nuclei become more stable?

   a) Nuclear Fusion

   b) Radioactive Decay

   c) Nuclear Fission

   Answer: b) Radioactive Decay

2. In what unit is activity measured?

   a) Watt

   b) Joule

   c) Becquerel (Bq)

   Answer: c) Becquerel (Bq)

3. What type of nuclear radiation consists of two neutrons and two protons?

   a) Beta Particle (β)

   b) Alpha Particle (α)

   c) Gamma Ray (γ)

   Answer: b) Alpha Particle (α)

Part 4 - Going Further:

Question: Explain the difference between count-rate and activity when measuring radioactive decay.

Answer: Count-rate is the number of decays recorded each second by a detector, while activity is the rate at which a source of unstable nuclei decays. Activity is the quantitative measure, usually expressed in becquerels (Bq), representing the number of decays per unit of time.

Part 5 - Revision Tips: Practice interpreting count-rate data and understanding the characteristics of different types of nuclear radiation.

Part 6 - More Help: 

Stay tuned for the next issue, where we'll explore more fascinating topics in GCSE Science.