Law of Radioactive Decay
A radioactive material first decays into and then decays to non-radioactive material . Which of the following figure represents time dependent mass of and ?
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Answer: (b)
- P only decays, so its mass falls exponentially from the start.
- Q starts at zero, rises while P feeds it, then falls as it decays to R: it has a maximum.
- R is stable, so it rises from zero and levels off when P and Q are used up.
- Only graph (b) shows this, so the answer is (b).