A radioactive decay generally occurs in unbalanced atoms of certain radioactive elements. It is the process that causes a huge amount of energy to be released into the surroundings in the form of ionizing radiation. The ionized radiations may include alpha particles, beta radiations, or gamma rays. Some of the elements present in nature such as uranium, thorium, etc. are originally unstable and radioactive in nature. Also, almost all of the elements present in nature consist of an unstable state. The unstable states or forms of the elements are typically radioactive in nature and are capable of emitting ionizing radiation into the surroundings. The elements that are capable of emitting ionizing radiations, as a result of the radioactive decay, are known as radionuclides. After undergoing radioactive decay, a radionuclide tends to get transformed into the atom of some other element, which is known as the decay product. The atom of the radioactive element gets transformed into a new decay product multiple times. This decay process carries on till the atom manages to find a stable state. If the unstable atom of a radioactive element undergoes radioactive decay for more than one time, then such an atom is called a series radionuclide. The series of decay products obtained as a result of the decay is known as the decay chain. The time taken by the half portion of the atoms present in the element to decay is known as the half-life of that particular element. The half-life of the radionuclide is the parameter that can be used to estimate the actual decay rate of the element. In other words, radioactive decay leads to the radioactivity of elements as the element tends to emit subatomic particles and energy spontaneously.
Types of Radioactive Emissions
There are basically three types of radioactive emissions that a radioactive element is capable of exhibiting.
1. Alpha Particles
The alpha particle emitted by the alpha decay of an element is a helium atom that is positively charged and consists of two protons. The alpha decay generally exists in the atoms that are bulky in size and consist of an imbalance in the number of neutrons and protons.
2. Beta Particles
Beta decay leads to the emission of neutrino and antineutrino particles into the environment. Such particles are relatively smaller in size and do not possess a charge. There exist two types of beta particles emitted by an atom during the radioactive decay process, namely beta minus or beta plus. Thus, the beta particles can be positively charged or negatively charged. The beta minus particle is generally represented by β− and is actually an electron that gets created in the nucleus of the atom. Likewise, the beta plus particle that is positively charged is the antiparticle of an electron. It is known as the positron and is generally represented by β+. These two beta particles tend to mutually annihilate each other when brought closer.
3. Gamma Radiations
Gamma radiations are electromagnetic radiations that fall between the energy range from 1-kilo electron volts (keV) to approximately 8 megaelectronvolts (MeV). These types of radiations are generally produced as a result of the gamma decay of an element. Gamma rays contain a number of photons that do not contain any charge polarity.
Examples of Radioactive Decay
There are a number of applications where we use the concept of radioactive decay in real life, some of them are listed below:
1. Smoke Detectors
One of the prominent applications of alpha decay can be observed in the smoke detectors installed in buildings. Smoke detectors typically make use of a radioactive element known as americium-241. The internal circuitry of the smoke alarm contains two charged plates, a battery, a detector circuit, and an alarming mechanism. The connections are made in such a way that one terminal of the battery is connected to the positive plate of the smoke detector, while the other terminal is connected to a detector of current. The detector of current is further connected to an alarm. The circuit gets completed by connecting the alarming system to the negative plate of the smoke detector. Americium-241 placed in the middle of the charged plates is capable of exhibiting alpha decay by releasing alpha particles into the surroundings. These alpha particles can be used to ionize the air molecules present in the surroundings. The ionisation of air molecules causes a significant amount of current to develop between the plates of the smoke detector. The magnitude of the current is quite high when ionization exists in the surroundings; therefore, the detector of the current does not ring the alarm. In case of fire, the smoke enters between the two charged plates of the smoke alarm and slows down the movement of ions between the plates, thereby decreasing the current. The detector of current detects the decrease in the magnitude of current and activates the alarming system.
2. Watches and Clocks
A number of watchmaking companies make use of certain radioactive elements to manufacture smartwatches. Usually, elements such as promethium-147 or hydrogen-3 are used as a source of light in various clocks and watches.
A huge variety of objects used in our daily life is composed of ceramic material. For instance floor and bathroom tiles, pots, utensils, etc. Most of these products make use of the radioactivity of naturally existing radioactive materials such as uranium, potassium, thorium, etc.
Glassware industries make use of a significant amount of radioactive elements such as potassium-40, thorium-232, etc. to enhance the glowing and lustrous appearance of an article. Usually, uranium that contains glass is known as canary or vaseline glass.
Radioactivity or radioactive decay of elements is also useful to the agriculture and farming industries. For instance, let us take the example of the fertilizer manufactured in an industry. The fertilizers generally make use of elements such as nitrogen, phosphorous, and potassium. Some of the fertilizers deployed into the fields also consist of a measurable quantity of certain radioactive materials. For instance, potassium is usually fit for such applications as it is a naturally existing radioactive element and is good for plant health.
6. Gas Lantern Mantles
A number of gas lantern mantles use the radioactive element thorium-232. The radioactive element used in such applications is required to undergo a series of radioactive decays to obtain a stable state.
7. Medicinal Equipment
A large number of machines make use of radioactive elements and their decay process to diagnose and cure certain chronic diseases such as tumours, cancers, etc.