A large collection of nuclei are undergoing alpha decay. The rate of decay at any instant is proportional to:
Correct answer: A. The number of un-decayed nuclei present at that instant
- A. The number of un-decayed nuclei present at that instant
- B. The time since the decay started
- C. The time remaining before all have decayed
- D. The half-life of the decay
Explanation
A option is accurate. The rate of radioactive decay is directly proportional to the number of undecayed (unstable) nuclei present at a given instant. As the number of undecayed nuclei decreases, the rate of decay also decreases because there are fewer nuclei available to decay.As the decaying atoms "∆N" is proportional to the time interval "∆t" and the number of atoms undecayed atoms "N". So,∆N ∝ N∆N ∝ ∆t
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Atomic nuclei contain protons and neutrons, with nuclear size, mass defect and binding energy describing their stability. The work covers alpha, beta and gamma decay, decay equations, half-life and decay rate, along with radiation safety and medical applications such as imaging, radiotherapy and tracers.
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