## Example of Radiometric Dating

The radium in a piece of lead decays at a rate governed by a first-order reaction.

### Example: Percentage after $1000$ Years

Let $Q$ be a sample of lead.

Let it be established that $10 \%$ of the radium decays in $200$ years.

After $1000$ years, there will be approximately $59.05 \%$ of the original amount of radium in $Q$.