How to Calculate Isotope Decay
What is Isotope Decay?
Radioactive decay follows first-order kinetics: N(t) = N₀·e^(-λt); half-life t₁/₂ = 0.693/λ; λ is decay constant.
Step-by-Step Guide
- 1Input isotope, half-life, and time elapsed
- 2Calculate remaining nuclei and activity
- 3Show decay curve
Worked Examples
Input
¹⁴C: t₁/₂ = 5730 years, after 11,460 years → 25% remains
Result
After 3 half-lives: 12.5% remains
Common Mistakes to Avoid
- ✕Assuming linear decay (exponential)
- ✕Using wrong half-life values
Frequently Asked Questions
Can decay rate change?
No, radioactive decay unaffected by temperature, pressure, chemical state.
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