Table of Nuclides
Frequently Asked Questions
|2.1: Decay Data|
|I have read of a "decay constant" in regard to radioactive decay. What is the "decay constant" of Potassium-40?|
|The decay of radioactivity by time is governed by
A(t)=A(0) exp(-lambda t)
where lambda = decay constant.
The half life it the time at which the radioactivity become half.
exp(-lambda T) = 0.5
T = ln(2) / lambda
K-40 half life is 1.277x10^9 year.
So lambda = 0.5428x10^-9 year^-1