Kinetics of Radioactive Decay

Question 1

Define radioactivity and list a few other terms that are used to describe
the process

Answer 1

Radioactivity is a process by which an unstable parent nucleus transforms
spontaneously into one or several daughter nuclei that are more stable than the parent
nucleus by having larger binding energies per nucleon than does the parent nucleus.
The daughter nucleus may be stable or may also be unstable and decay further
through a chain of radioactive decays until a stable nuclear configuration is reached.
Radioactive decay is usually accompanied by emission of energetic particles, γ rays
or both.

Question 2

Name and define the characteristic parameter that is used to describe a
given radioactive process. Discuss the dependence of this parameter on
prevailing physical conditions in radioactive atom’s environmen

Answer 2

All radioactive decay processes are governed by the same general formalism
that is based on the definition of the activity A(t) and on the total radioactive decay
constant λ that is a characteristic parameter for each radioactive decay process with
dimensions of reciprocal time usually in s−1. The decay constant λ is independent of
the age of the radioactive atom and is essentially independent of physical conditions
such as temperature, pressure, and chemical state of the atom’s environment.

Question 3

In a radioactive substance that contains a large number N of identical
radioactive atoms, what is the probability that a given atom will decay
during a time interval t? Are there any restrictions on the magnitude
of t?

Answer 3

The total radioactive decay constant λ multiplied by a time interval t that
is much smaller than 1/λ represents the probability that any particular atom of radioactive
substance containing a large number N(t) of identical radioactive atoms
will decay in that time interval