Radioactivity Meaning
Radioactivity is the emission of ionizing radiation or particles as a result of the disintegration or breakdown of atomic nuclei.
Wherever there is a nuclear instability, the atom’s nucleus undergoes the phenomenon of radioactivity. The radioactivity results in nucleus decay.
Wherefore, the unstable nuclei spontaneously decay into their most stable configuration by emitting certain particles or in the form of electromagnetic radiation.
In the present time, radioactivity, such as radioisotopes has various applications in diagnosis and therapy.
This page discusses in-depth the uses of radioactive substances with the application of radioactivity.
What is Radioactivity?
Many day-to-day activities in nature take place around us that we are unaware of.
Further, processes like emission and absorption are some of the phenomena that take place unknowingly.
When emission or absorption takes place in the atom. This is the place where a stable property of nature comes, we call this stability the Radioactivity.
Radioactivity is one of the scientific properties of matter where the emission of supersonic subatomic particles takes place spontaneously.
On this page, we will focus more on the two following things:
Uses of radioactivity
Application of radioactivity
Application of Radioactive Isotopes
Radioisotopes have a wide range of use in diagnosis and therapy.
Further, this has led to a rapidly growing field named nuclear medicine.
The radioactive isotopes are perfectly effective as tracers in certain diagnostic procedures.
Ordinarily, radioisotopes are chemically alike to stable isotopes of the same element.
Because of this reason, they can take the place of the latter in physiological processes.
Moreover, detection devices as gamma-ray spectrometers and proportional counters can readily trace the radioisotopes even in minute quantities.
Though many radioisotopes likewise iodine-131, phosphorus-32, and technetium-99m are among the most important tracers.
Applications of Radioactivity
1. In Medicines
Physicians find iodine-131, the best radioisotope for determining the following:
Cardiac output
Plasma volume
Fat metabolism
Particularly, to measure the activity of the thyroid gland where this isotope piles up.
Physicians also use Phosphorus-32 for identifying malignant tumours. It’s because cancerous cells accumulate phosphates more than normal cells do.
Additionally, Technetium-99m is also used with radiographic scanning devices.
Technetium-99m radioisotopes are also rich for examining the anatomic structure of organs.
Moreover, radioisotopes like Cobalt-60 and cesium-137 are used to treat cancer.
Also, they can administer malignant tumours to minimize damage to adjacent healthy tissue.
Furthermore, there are other uses of radioactive substances that we will discuss:
2. Industrial Use
For the most part, radioactivity has the most important industrial applications in power generation as a result of the release of the fission energy of uranium.
Other applications include the use of radioisotopes to measure/control the thickness/density of metal and plastic sheets.
Industrialists also find uses of radioactive substances in the following works:
Firstly, to stimulate the cross-linking of polymers.
Secondly, to induce mutations in plants to develop harder species.
Thirdly, to preserve certain kinds of foods by killing microorganisms that cause spoilage.
Lastly, in tracer applications, radioactive isotopes are employed.
For instance, in automobile engines, we find the uses of radioactive substances measuring the effectiveness of motor oils on the wearability of alloys for piston rings and cylinder walls.
Use of Radioactivity
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Research in the Earth sciences has benefited scientists greatly by the use of radiometric dating techniques.
These techniques rely on the principle that a particular radioisotope (radioactive parent) in geologic material decays at an invariant known rate to daughter isotopes.
Using such techniques, investigators have determined the ages of various rocks and rock formations and thereby quantified the geologic time scale, also known as Absolute dating.
Carbon Dating
A special application of this type of radioactivity age method is carbon-14 dating, This application has proven to be useful especially to physical anthropologists and archaeologists.
Additionally, it has helped researchers to better determine the chronological sequence of past events by enabling them to date more accurately fossils and artifacts from 500 to 50,000 years old.
Radioisotopic Tracers
Radioisotopic tracers are very helpful in environmental studies. For instance, studying water pollution in rivers and lakes and air pollution by smokestack effluents.
They are also used to measure deep-water currents in oceans and snow-water content in watersheds.
Researchers in the biological sciences, too, make maximum use of radioactive tracers to study complex processes.
For instance, thousands of plant metabolic examinations are conducted on amino acids and compounds of sulfur, phosphorus, and nitrogen.
Application of Radiochemistry
Radiochemistry uses radioisotopes to primarily deal with the study of chemical reactions of non-radioactive isotopes.
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Besides this, it finds application in the medical field and environmental management.
The Important Applications of Radioisotopes are:
Radiocarbon Dating: This method helps determine the age of fossil wood or animal by using the C -14 isotope.
Study of Chemical Reactions: By mixing a radioisotope with a non-radioactive isotope of the reactants, the nature of some of the chemical reactions can be studied.
The radioisotope used for this purpose is a radiotracer.
For example, by photosynthesis plants synthesize carbohydrates from carbon dioxide and water as described in the following reaction.
12 CO2 + 12 H2O → produces → 2 C6H12O6 + 12 O2
Carbon dioxide Water Sugar Oxygen
Here, a question arises: did the oxygen evolved in this process come from CO2 or H2O?. However, by using radioisotope O -18 as a tracer, we find that the evolved oxygen comes from H2O.
FAQs on Applications of Radioactivity
1. What are the major fields where radioactivity is applied?
Radioactivity has numerous applications across various fields. The most significant ones include:
- Medicine: Used for both diagnostics (imaging) and therapy (cancer treatment).
- Archaeology and Geology: Used in radiometric dating techniques like carbon-14 dating to determine the age of fossils and rocks.
- Industry: Applied in power generation through nuclear fission, measuring the thickness of materials, and sterilising equipment.
- Agriculture: Used to develop new plant species through induced mutation and to preserve food by killing microorganisms.
- Scientific Research: Employed as tracers to study complex biological and chemical processes, such as photosynthesis.
2. How is radioactivity used in the medical field for diagnosis and treatment?
In medicine, radioactivity is crucial for both diagnosis and therapy. For diagnosis, radioactive isotopes (radioisotopes) like Iodine-131 and Technetium-99m are used as tracers. They are introduced into the body and their movement is tracked to examine organ function, such as thyroid activity or blood flow. For therapy, high-energy radiation from sources like Cobalt-60 is used in radiotherapy to target and destroy cancerous tumours while minimising damage to surrounding healthy tissue.
3. What is the principle behind carbon dating, a key application of radioactivity?
The principle of carbon dating relies on the radioactive isotope Carbon-14 (C-14). Living organisms constantly absorb C-14 from the atmosphere. When an organism dies, this absorption stops, and the C-14 within its remains begins to decay at a known, constant rate (a half-life of about 5,730 years). By measuring the ratio of remaining C-14 to stable Carbon-12 in a fossil or artefact, scientists can accurately determine its age.
4. What are some important industrial applications of radioactivity?
In industry, radioactivity is used in several important ways:
- Power Generation: Nuclear power plants use the energy released from the fission of uranium atoms to generate electricity.
- Quality Control: Radiation is used to measure and control the thickness and density of materials like plastic sheets and metal without physical contact.
- Sterilisation: Gamma rays are used to sterilise medical equipment and preserve certain foods by killing harmful bacteria and microorganisms.
- Tracer Studies: Radioisotopes are used to measure the wear and tear on machinery, like piston rings in engines, by tracking the movement of tiny radioactive particles.
5. Why are certain radioisotopes like Technetium-99m so effective for medical imaging?
Radioisotopes like Technetium-99m are effective for medical imaging for two main reasons. First, they are chemically similar to stable elements and can be attached to molecules that participate in specific physiological processes, allowing doctors to observe organ function. Second, they emit detectable gamma rays but have a short half-life, meaning they provide a clear image and then decay quickly, minimising the radiation dose and potential harm to the patient.
6. How does radioactivity allow scientists to study chemical reactions like photosynthesis?
Radioactivity allows scientists to use radioisotopic tracers to map out complex chemical reaction pathways. For example, to determine if the oxygen released during photosynthesis comes from water (H₂O) or carbon dioxide (CO₂), scientists used water containing a radioactive isotope of oxygen (O-18). When they found that the oxygen gas released was radioactive, it proved that the oxygen originated from the water molecules, not the carbon dioxide. This technique provides definitive evidence that is otherwise difficult to obtain.
7. What is the key difference between the terms 'radioactivity' and 'radioisotope'?
The key difference lies in their definitions. Radioactivity is the natural phenomenon or process by which an unstable atomic nucleus loses energy by emitting radiation. It is a property of matter. A radioisotope, on the other hand, is an atom that has an unstable nucleus and exhibits the property of radioactivity. In simple terms, radioactivity is the process, and a radioisotope is the specific type of atom that undergoes that process.
8. While radioactivity is useful, what are the primary risks associated with its application?
The primary risks of radioactivity stem from the damaging effects of ionising radiation on living tissue. The main concerns are:
- Tissue Damage: High doses of radiation can destroy healthy cells, leading to radiation sickness or death. Even in targeted therapies like cancer treatment, there is a risk of damaging adjacent healthy tissue.
- Genetic Mutation: Radiation can damage DNA, potentially leading to cancer or genetic defects.
- High Cost and Handling: Radioactive materials are expensive and require specialised, secure facilities and trained personnel for safe handling and disposal to prevent environmental contamination.
