1. What is Specific Activity of an Isotope?

Definition: Specific Activity is defined as the concentration of radioactivity or the relationship between the mass of radioactive material and its activity.

Purpose: It helps nuclear scientists and researchers determine the radioactivity per unit mass of a radioactive substance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A_s \) — Specific Activity (Becquerel per Kilogram)
• \( \lambda \) — Activity of Radioactive Substance (Becquerel)
• \( N_A \) — Avogadro's Number (6.02214076×10²³ mol⁻¹)
• \( M \) — Atomic Weight of Nuclide (Kilogram)

Explanation: The activity is multiplied by Avogadro's number and divided by the atomic weight to get specific activity.

3. Importance of Specific Activity Calculation

Details: Specific activity is crucial in nuclear medicine, radiopharmaceuticals, and radiation safety to determine the concentration of radioactivity in materials.

4. Using the Calculator

Tips: Enter the activity in Becquerels and the atomic weight in kilograms. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Avogadro's number?
A: Avogadro's number (6.02214076×10²³) is the number of constituent particles (usually atoms or molecules) in one mole of a substance.

Q2: What units should I use for atomic weight?
A: The atomic weight should be entered in kilograms for this calculation.

Q3: How is activity different from specific activity?
A: Activity measures total disintegrations per second, while specific activity measures disintegrations per second per unit mass.

Q4: What's a typical specific activity value?
A: This varies greatly by isotope. For example, Cobalt-60 has a specific activity of about 4.2×10¹³ Bq/g.

Q5: Can I use this for any radioactive isotope?
A: Yes, as long as you know the activity and atomic weight of the nuclide.