Radioactive Decay Calculator
Determine the remaining activity of a radioactive isotope after a specific elapsed time.
Calculation Parameters
Adjust the values below.
Calculated Result
Expert Tip
Ensure units are correctly formatted (e.g. Kelvin for gas temperatures and liters for volumes) to get chemically accurate outputs.
How this Calculator Works
This calculator allows you to solve Radioactive Decay problems dynamically. Adjust the input parameters using the sliders or selection menu below:
- Initial Activity (A0, Bq) (Range: 1 to 10000, Default: 1000)
- Isotope Half-Life (t1/2, days) (Range: 1.0 to 365.0, Default: 8.0)
- Decay Time Elapsed (t, days) (Range: 1 to 100, Default: 16)
The results are computed instantly and updated in the results panel on the right.
Formula & Methodology
where λ = ln(2) / t_1/2
Where:
- Initial Activity: Parameter value.
- Isotope Half-Life: Parameter value.
- Decay Time Elapsed: Parameter value.
Step-by-Step Calculation Example
To calculate Radioactive Decay manually, follow these steps:
- Identify the input parameters. For example:
- Initial Activity (A0, Bq) = 1000
- Isotope Half-Life (t1/2, days) = 8.0
- Decay Time Elapsed (t, days) = 16
- Apply the formula:
A_t = A_0 * e^(-λ * t)
where λ = ln(2) / t_1/2 - Verify the calculated value which is updated instantly in the results panel on the right.
Frequently Asked Questions
What is the radioactive decay law? ▼
N(t) = N0 × e^(-λ × t), where N(t) is remaining quantity, N0 is initial quantity, λ is decay constant, and t is elapsed time.
What are common units of radioactive activity? ▼
Activity is measured in Becquerels (Bq, 1 decay/sec) or Curies (Ci, 3.7 × 10¹⁰ decays/sec).
What is Carbon-14 dating half-life? ▼
Carbon-14 has a half-life of 5,730 years, used to date organic archaeological artifacts up to ~50,000 years old.