Physics 0625 · IGCSE · Radioactivity

Radioactivity — practice question

Lead-202 has a half-life of $52\,500$ years. A sample of lead-202 gives $800$ counts$/\text{s}$. After how many years will the count rate decrease to $100$ counts$/\text{s}$?

  • A$105\,000$ years
  • B$157\,500$ years
  • C$210\,000$ years
  • D$420\,000$ years

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