Chapter 2
Radioactivity
2.1 Introduction
This chapter is devoted to covering various aspects of radioactivity. It encompasses
properties of particulate (i.e., α, β, and positron) radiations and electromagnetic
radiation, the law of radioactive decay, and the statistics of counting. The emission
of radiations from a radioactive material comes from the fact that a radioactive isotope
is unstable and it converts to a stable isotope by emitting radiations like α, β, positron,
γ -rays, etc. In order to understand the nature of these radiations, it would be pertinent
to recall atomic and nuclear structures in brief.
When atomic nuclei have a greater or lesser number of protons or neutrons than
what is required for a stable nucleus, they rearrange their nucleons in order to achieve a
more stable neutron/proton ratio; this rearrangement is independent of the chemical or
physical state of the element. Sometimes, the nucleus may undergo a series of changes
before it ultimately attains stability. The unstable nuclides are known as “radioactive
isotopes” and the phenomenon of radiation emission is called “radioactivity”. The
method of rearrangement is called a “decay process”, and is independent of past
life or method used for the production of nuclei. Based on pure thermodynamic
consideration of mass defect, radioactivity and possible types of radioactive decays
are discussed in the forthcoming sections.
If mass defect is positive, then the process is said to be exoergic decay and if
negative, then we call it endoergic decay. Based on mass defect and thermodynamic
consideration, one can classify the radioactive nuclides’ decay under three main
headings.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9_2
13
Radioactivity
2.1 Introduction
This chapter is devoted to covering various aspects of radioactivity. It encompasses
properties of particulate (i.e., α, β, and positron) radiations and electromagnetic
radiation, the law of radioactive decay, and the statistics of counting. The emission
of radiations from a radioactive material comes from the fact that a radioactive isotope
is unstable and it converts to a stable isotope by emitting radiations like α, β, positron,
γ -rays, etc. In order to understand the nature of these radiations, it would be pertinent
to recall atomic and nuclear structures in brief.
When atomic nuclei have a greater or lesser number of protons or neutrons than
what is required for a stable nucleus, they rearrange their nucleons in order to achieve a
more stable neutron/proton ratio; this rearrangement is independent of the chemical or
physical state of the element. Sometimes, the nucleus may undergo a series of changes
before it ultimately attains stability. The unstable nuclides are known as “radioactive
isotopes” and the phenomenon of radiation emission is called “radioactivity”. The
method of rearrangement is called a “decay process”, and is independent of past
life or method used for the production of nuclei. Based on pure thermodynamic
consideration of mass defect, radioactivity and possible types of radioactive decays
are discussed in the forthcoming sections.
If mass defect is positive, then the process is said to be exoergic decay and if
negative, then we call it endoergic decay. Based on mass defect and thermodynamic
consideration, one can classify the radioactive nuclides’ decay under three main
headings.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9_2
13