What is specific activity, and how does it differ from activity?

What is specific activity, and how does it differ from activity?

• A. Specific activity is activity per unit mass (or per unit amount) of a radionuclide; it measures radioactivity concentration independent of total mass.
• B. Specific activity is the total activity of a sample regardless of mass.
• C. Specific activity refers to the energy of emitted photons.
• D. Specific activity is the rate of decay of a single nucleus.

Answer: (A)