📚 Topic Summary
Gamma decay is a type of radioactive decay where an unstable atomic nucleus releases energy in the form of gamma rays (high-energy photons). This process occurs when the nucleus has excess energy after undergoing other types of decay, such as alpha or beta decay. Unlike alpha or beta decay, gamma decay does not change the number of protons or neutrons in the nucleus, it simply lowers the energy state of the nucleus.
The half-life of a radioactive isotope undergoing gamma decay is the time it takes for half of the atoms in a sample to decay. Activity refers to the rate at which the decay occurs, typically measured in Becquerels (Bq) or Curies (Ci). Experiments measuring half-life and activity involve detecting and quantifying the emitted gamma rays using specialized detectors.
🧮 Part A: Vocabulary
Match the term with its definition:
- Term: Half-life
- Term: Gamma Ray
- Term: Activity
- Term: Isotope
- Term: Decay Constant
- Definition: The rate at which radioactive decay occurs.
- Definition: A high-energy photon emitted during radioactive decay.
- Definition: Atoms with the same number of protons but different numbers of neutrons.
- Definition: The time it takes for half of the radioactive atoms to decay.
- Definition: The probability of decay of a nucleus per unit time ($λ$).
(Match the terms to the definitions. For example: 1-D, 2-A, etc.)
✍️ Part B: Fill in the Blanks
Gamma decay involves the emission of _______ rays from an unstable _______. This process _______ change the atomic number or mass number of the atom. The _______ is the time it takes for half of the radioactive material to decay. The rate of decay is known as the _______.
(Possible words: gamma, does not, nucleus, half-life, activity)
🤔 Part C: Critical Thinking
Explain how understanding the half-life of a gamma-emitting isotope is important in medical applications such as radiation therapy or diagnostic imaging. Give a specific example.
