Decay Constant

Radioactivity is a random process; it is impossible to predict exactly when a particular nucleus will decay.

However, it is possible to determine the probability that a nucleus will decay in a given time.

For a particular decay mechanism, the radioactive decay constant for a nuclide is defined as the probability per unit time that a given nucleus of that nuclide will decay by that mechanism. The radioactive decay constant is usually represented by the symbol λ. 

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Exponential Decay of Activity
Quantum and Nuclear PRACTICAL PHYISCS

Some useful equations for half-lives

The rate of decay of a radioactive source is proportional to the number of radioactive atoms (N) which are present.

Teaching Guidance 14-16

Exponential Decay of Activity
Quantum and Nuclear IOP TAP

Episode 515: The radioactive decay formula

Here, the key idea is the random nature of the decay. Avoid simply pulling pull equations out of the air – at least make them...

Lesson 16-19

Decay Constant
Quantum and Nuclear IOP Glossary Project

Decay constant, radioactive

For a particular decay mechanism, the radioactive decay constant for a nuclide is defined as the probability per unit time...

Glossary Definition 16-19

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