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Introduction
Initially coined in the year 1896, the phenomenon of radioactivity is exhibited by the atom’s nucleus as a result of nuclear instability. In simple terms, radioactivity can be described as a process through which the unstable atom’s nucleus tends to lose its energy after emitting radiation. A small quantity of Uranium compound was packed in the black paper and placed in a drawer that contained photographic plates. When examined, it was recorded that the plates had been exposed to some exposure which was later termed radioactive decay. There are mainly three types of radioactive decay. These include the Alpha decay, beta decay, and gamma decay which we will be studying in this article.
Today, in this article on the Law of radioactive decay, you will get detailed information on the half life of radioactive elements, Types of radioactivity decay, their properties, and other related topics. So, without further ado, let us get started with the Law of radioactive decay in the physics study material.
Explain the Law of radioactivity decay
According to the radioactivity decay law, the probability per unit time that the nucleus will most likely decay remains the same and independent of time. radioactive disintegration is impossible to forecast due to the nucleus’s smaller size than the atom and the magnitude of the electromagnetic force.
The atomic nucleus is located in the centre of the atom, which is shielded from the environment by surrounding electrons. As a result, the study of the element’s environment-independent degradation.
In mathematical terms, the Law of radioactivity decay is described as –
A∝N
A=λN (mathematical representation)
A represents the no. of decays per unit time of a radioactive sample
N represents the total number of particles in the sample
λ is the constant of proportionality or decay constant
Types of the Radioactivity Decay
There are mainly three different types of radioactivity decay. These are as follows –
- Alpha Decay
Alpha decay can be described as the phenomena of alpha particles emission from the radioactive nucleus. The alpha particles hold the least amount of penetration power whereas the highest ionisation power.
- Beta Decay
Mostly, the beta particle is known as the electron; however, it can be positron as well. In case the overall reaction includes electrons, the neutrons are shredded by the nucleus one after another. Also, the proton number keeps on increasing. Beta particles are highly energetic which are present inside the nucleus.
- Gamma Decay
The photon is emitted in case the electron jumps from extremely high energy to extremely low energy levels. Similarly, it happens in the nucleus as well, which gives rise to the gamma rays. The gamma rays are the uncharged particles and have electromagnetic radiation. Gamma particles have the greatest penetrating power.
Properties of Alpha, beta, and Gamma
Although most of the properties of apha, beta and gamma have already been discussed. Here is the detailed comparison between the properties of alpha, beta and gamma radiations:
Property | α ray | β ray | γ ray |
Particle’s nature | The alpha rays are positively charged particles that consist of 4He2 nuclei. | The beta rays are negatively charged. Note these are also known as electrons. | The gamma rays are uncharged particles and have electromagnetic radiation. |
Charge on the particles | The alpha rays have two units of positive (+) charge. This means it is +2e. | The beta rays consist of only one unit of negative charge. This means it is e–. | The gamma rays contain absolutely no charge. |
Mass of the particles | The mass of the alpha particles is 6.6466 × 10-27 kg. | 9.109 × 10-31 kg is the mass of the beta particles. | The gamma rays have absolutely no mass. |
Range of the particles | Alpha rays are ~10 cm in air. It can be stopped by 1 mm of aluminium metal sheet. | Beta rays are up to a few meters in the air. It can be stopped easily using a thin layer of aluminium mass. | Gamma rays are several metres in the air. It can be stopped through a thick lead layer. |
Natural sources of the particles | The alpha rays are naturally radiated through the natural radioisotopes e.g. 236U92. | The beta rays are naturally radiated through the cobalt radioisotopes e.g. 68Co29. | The gamma rays form excited nuclei. |
Conclusion
With this, we end our study material on the Law of radioactive decay. In this Introduction Law of radioactive decay, we studied that the loss of elementary particles from an unstable nucleus causes radioactive disintegration, transforming the unstable material into a more stable element. There are three types of radioactive decay. These include alpha decay, beta decay, and gamma decay.
We covered Introduction to the Law of radioactive decay, types of radioactive decay, a brief introduction of all three types of decay and other related topics in detail. We hope the Law of radioactive decay study material must have helped attain a greater understanding of this topic.
