Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Activity (Bq)

Total activity of the sample.

Sample mass (g)

Mass of the sample; must be greater than zero.

Compute the specific activity of a radioactive sample as activity divided by sample mass. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Specific activity (Bq/g)

Activity per gram of sample.

• The result is conditional on the stated model, constants, standard state, temperature, pressure, composition, and unit basis. Real mixtures and measurements can depart from ideal behavior and carry uncertainty not represented by a single calculated value.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Activity Decay Calculator

  Compute the radioactive activity after a time as A = A₀·e^(−λt) with λ = ln2/t½.

• Combustion Carbon Mass Calculator

  Compute the carbon contained in a burned sample from the CO₂ collected during combustion analysis.

• Combustion Hydrogen Mass Calculator

  Compute the hydrogen contained in a burned sample from the H₂O collected during combustion analysis.