1. What is a Radiation Decay Calculator?

Definition: This calculator determines the remaining activity of a radioactive substance after a given time period using the exponential decay law.

Purpose: It helps nuclear physicists, radiologists, and students understand how radioactive materials decay over time.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Current activity (Becquerels)
• \( A_0 \) — Initial activity (Becquerels)
• \( \lambda \) — Decay constant (per second)
• \( t \) — Time elapsed (seconds)
• \( e \) — Euler's number (~2.71828)

Explanation: The initial activity decreases exponentially over time based on the substance's decay constant.

3. Importance of Radiation Decay Calculation

Details: Accurate decay calculations are essential for radiation safety, medical treatments, radiometric dating, and nuclear waste management.

4. Using the Calculator

Tips: Enter the initial activity in Bq, decay constant in s⁻¹, and time in seconds. All values must be positive (time can be zero).

5. Frequently Asked Questions (FAQ)

Q1: How is decay constant related to half-life?
A: Decay constant (λ) = ln(2) / half-life. They are inversely proportional.

Q2: What's the difference between Bq and Ci?
A: 1 Ci = 3.7×10¹⁰ Bq. Becquerel is the SI unit (1 decay per second), while Curie is based on radium-226's activity.

Q3: Can I use this for any radioactive isotope?
A: Yes, as long as you know its decay constant or can calculate it from half-life.

Q4: Why does the result have so many decimal places?
A: Radioactive decay calculations often require high precision, especially for low-activity or long-lived isotopes.

Q5: How do I find the decay constant for a specific isotope?
A: Look up the isotope's half-life (t½) and calculate λ = ln(2)/t½.