Select specific activity, half-life, molar mass, activity or mass. This pure single-radionuclide model excludes carrier mass and daughter activity; radioactivity is not radiation dose.

Pure single radionuclide only; excludes carrier mass and daughter activity. Activity is not radiation dose or a handling-safety assessment.

Optional settings

Fills half-life and molar mass. Values remain editable; use evaluated data for precision work.

Specific Activity Formula

The following formula calculates specific activity for a pure single radionuclide. The coefficient is rounded and uses a 365.25-day year.

a = 1.32X10¹⁶ / (T1 / 2 × M)
  • Where a is the specific activity (Bq/g)
  • T1/2 is the half-life (years)
  • M is the molar mass (g/mol)

Specific Activity Definition

Specific activity is a measure of activity per quantity of a radionuclide. Activity is a measure of the number of radioactive transformations per second that occur.

Specific Activity Example

How to calculate specific activity?

  1. First, determine the half-life.

    Calculate the half-life of the nuclide. You can use the calculator linked above for more help on this.

  2. Next, determine the molar mass.

    Calculate or measure the molar mass in grams per mole.

  3. Finally, calculate the specific activity.

    Calculate the specific activity using the formula above.

FAQ

What is a radionuclide?

A radionuclide is the nucleus of a radioactive material.

Specific Activity Calculator screenshot
specific activity formula