Contents
Key Stage 5
Meaning
A decay curve is an exponential decrease curve showing how the mass or activity of a radioactive isotope decreases with time.
About Decay Curve
Represents the rate of decay of a radioactive substance. Shows the characteristic exponential decay pattern of radioactive materials. Used to determine the half-life of a radioactive substance. Helps in understanding the stability and longevity of isotopes.
Formula
The curve is described by the equation
\(𝑁(𝑡)=𝑁_0𝑒^{−𝜆𝑡}\)
\(𝑁(𝑡)=𝑁_02^{−𝑡/𝑡_{1/2}}\)
Where:
𝑁(𝑡) is the number of undecayed nuclei at time (𝑡)
𝑁0 is the initial number of nuclei
𝑡 is the time reading from the start of the experiment
𝜆 is the decay constant for the isotope.
t1/2 is the half-life of a given isotope
Examples
The decay curve of Uranium-238 showing its decrease over millions of years. Monitoring the decay curve of medical isotopes to ensure they remain effective for treatment.