Radioactive decay is a spontaneous process whereby unstable atomic nuclei is broken down into more stable constituents. This is also accompanied by the release of energy in the single form of radiation. Radioactive decay is a natural process that gives us a glimpse into understanding the actions of atoms and their subatomic makeup.
Thanks to scientists like Henri Becquerel and Marie Curie who pioneered the field of Radioactive decay, the discovery of Radioactive decay which can be traced back to the late 19th century was very quick in becoming something that can be used into exploring the intricacies of atomic processes. This in turn lead to various advancements in Medicine, Science, and many technologies handled today.
The Basics of Radioactivity
To understand Radioactivity, we need to understand what atoms are. Fundamentally, Atoms are the building blocks of matter. The constituents of atoms include protons, neutrons, and electrons which can be found in their respective locations in the atoms. How these three constituents are balanced within the atom determines how stable the atom is.
We also need to understand what elements and isotopes are. Firstly, An element is defined by the number of proton it has in its nucleus, meaning elements are named by the different number of protons they possess. An isotope, however, has the same number of protons but a different number of neutrons. How do Isotopes relate to Radioactivity? Well, some isotopes, called radioactive isotopes, are by design unstable. Overy a period of time, these isotopes will undergo some spontaneous changes in order of achieving a more balanced state. As a result of this transformation, radiation is emitted.
Types of radioactive decay
There are mainly three types of radioactive decay. We have alpha, beta, and gamma decay, each with their own unique characteristics.
Alpha decay is involved with the emission of an alpha particle. An alpha particle is made up of two protons and two neutrons. Alpha decay can only occur in a very neutron-rich nuclei, looking to have a more stable configuration. The nucleus of an element automatically transforms into a new element that is two places lower in the periodic table whenever an alpha particle is released. When an alpha particle is emitted, it can travel for up to just 1-3cm before dissipating. They can barely penetrate through any material so handling them is more safe than handling beta and gamma decay. Uranium-238 is an example of a Uranium isotope that undergoes alpha decay to transform into Thorium-234, resulting in the release of an alpha particle. The emission of an alpha particle can be expressed as the following:
\begin{array}{l}_{Z}^{A}\textrm{X}\rightarrow _{Z-2}^{A-4}\textrm{Y}+_{2}^{4}\textrm{He}\end{array}
In a Beta decay, a transformation occurs. In the nuclei of an element, the neutron is transformed into a proton which we call a beta-plus decay or a proton is transformed into a neutron which we call a beta-minus decay. This process is then followed by the emission of a beta particle. The atomic structure is transformed into a more stable configuration thanks to the emission of the beta particle which is an electron or positron. Beta particles can travel through several centimeters or even meters of air. Beta particles can also penetrate skin an even cause damage such as skin burns. Carbon-14, a Carbon isotope when undergoes beta decay is transformed into Nitrogen-14. This process is actually an essential process in carbon dating techniques which helps us put an age to organic materials in our world. Beta decay can be expressed in the following:
Beta-minus decay:
\begin{array}{l}_{Z}^{A}\textrm{X} \rightarrow _{Z+1}^{A}\textrm{Y} + e^{-} + \bar{\nu }\end{array}
\begin{array}{l}N = p + e^{-} + v^-\end{array}
Beta-plus decay:
\begin{array}{l}_{Z}^{A}\textrm{X} \rightarrow _{Z-1}^{A}\textrm{Y} + e^{+} + {\nu }\end{array}
\begin{array}{l}P = n + e^+ + v \end{array}
Gamma decay is concerned with the emission of high energy gamma rays. This process often occurs after an alpha or beta decay. In a gamma decay, the electromagnetic waves that are released lact mass but in turn can carry a significant amount of energy. When it comes to penetrating ability, nothing quite compares to Gamma rays. Gamma rays can travel up to hundreds of feet in the air before dissipating. Gamma rays have so much penetrating ability that several inches of a dense material like concrete or even lead is required to stop them. When Cobolt-60 undergoes a gamma decay to transform into Nickel-60, a beta particle is released followed by gamma rays. This extensive process is used in several industrial applications as well as medical treatments. Gamma decay can be expressed in the following:
\begin{array}_{Z}^{A} X^{*} \rightarrow{ }_{Z}^{A} X+\gamma \nonumber\end{array}
The decay that occurs in alpha, beta, and gamma decay, alters the atomic composition of an element, leading to the creation of whole new elements as well as isotopes. Radioactive decay finds uses in several fields including medicine, environmental studies, and the Industrial field. The differences between the three decays is evident in the particles they emit during the processes and the different penetrating capabilities that each possess, with alpha decay being the least capable and gamma being the most.
Half-life in radioactive decay
Another key concept that is essential in understanding radioactive decay is half-life. In order to be able to predict the action and behaviors of radioactive materials over time, half-life is used. Essential it is the amount of time it takes for the half of a sample to undergo decay. Decay is a random process, but when a significant sample is used, predictions can be made.
In order to calculate half-life, the formula:
\begin{array}{l} N = N_{0}e^{-\lambda{t}}\end{array}
Where:
N = quantity of the substance remaining
N0 = initial quantity of the substance
t = time elapsed
λ = decay constant
.
Let’s take a random isotope which has a half-life of 10 years for example. After 20 years, only a quarter of the original material will remain.
Another example of this can be if an Isotope has a half-life of one hour, after two hours, two half lives would have elapsed causing the whole sample to decay.
In summary, radioactive decay is a key concept that helps us understand atomic behaviors of elements and isotopes, with alpha, beta, and gamma decay playing major roles in the process. From the discoveries of modern applications to aiding in scientific research, the study of radioactive decay continues to be one of those fields that we cannot move further without. It is a powerful tool, and as such, using the appropriate safety measures can help ensure the continued impact of this natural phenomenon.
Frequently asked questions (FAQs)
Q1 – What are the three types of radioactive decay?
There are mainly three types of radioactive decay. We have alpha, beta, and gamma decay, each with their own unique characteristics.
Q2 – What is radioactive decay?
Radioactive decay is a spontaneous process whereby unstable atomic nuclei is broken down into more stable constituents.
Q3 – What is half-life in radioactive decay?
Half-life in radioactive decay is the amount of time it takes for the half of a sample to undergo decay. Decay is a random process, but when a significant sample is used, predictions can be made.
