Why Are Carbon Isotopes Important in Chemistry?
Isotopes are atoms that have the same number of protons but differ in the number of neutrons they contain. Isotopes of elements frequently have varied masses due to differing numbers of neutrons. Even atomic number elements often have three or more stable isotopes, whereas odd atomic number elements typically have one or two stable isotopes. There are, however, some outliers, such as carbon, helium, and beryllium.
This is the simple form of isotopes definition. The name of the particular element is commonly used to signify or identify an isotope, which is followed by a hyphen and the mass number. Let us look at the isotopes of carbon in detail from this article.
Overview
The term "isotope" refers to the variation in an element's atomic mass or weight. The word isotope is derived from the Greek words isos and topos, which both mean "the same location." So the name comes from the fact that isotopes of a single element are found in the same place on the periodic table.
Margaret Todd, a Scottish doctor and writer, coined the term while working with radiochemist Frederick Soddy. This word was first used in 1913.
Properties of Isotopes
Let us study the physical and chemical properties of isotopes here.
When it comes to chemical properties, isotopes of a certain element are almost similar or identical. Different isotopes have nearly identical chemical characteristics. Isotopes have distinct physical qualities, such as mass, melting or boiling temperature, density, and freezing point.
The physical properties of every isotope are mostly dependent on its mass. We can distinguish one isotope from another by understanding the differences.
Types of Isotopes
The types of isotopes or the list of isotopes can be given as follows:
Isotopes are classified as stable or radioactive. As a result, radioactive isotopes are often referred to as radioisotopes or radionuclides.
Stable isotopes or stable nuclides are isotopes that do not decay radioactively.
According to the findings, the planet Earth contains approximately 339 naturally occurring nuclides or isotopes.
286 of these are reported to be primordial nuclides, which are thought to have existed since the Solar System's formation.
Examples of Isotopes
Let us look at a few of the examples of isotopes from this section.
Isotopes of hydrogen and carbon are common examples of isotopes. When it comes to hydrogen, there are three stable isotopes: protium, deuterium, and tritium. Protium, deuterium, and tritium all have the same number of protons but differing numbers of neutrons, with protium having zero, deuterium having one, and tritium having two.
When it comes to carbon, there are three isotopes: Carbon-12, Carbon-13, and Carbon-14. The atomic masses of the isotopes are 12, 13, and 14. Carbon-12 is a stable isotope in this scenario, whereas carbon-14 is primarily a radioactive isotope.
Other common isotopes include: Tin has 22 isotopes, Zinc has 21 known isotopes, Neon is a mixture of 3 isotopes, natural xenon is a mixture of 9 stable isotopes, and Nickel has 14 known isotopes. This is a small list of isotopes in detail.
Formation of Isotopes
Nuclear processes in stars originated and continue to create all elements heavier than hydrogen, including all of their isotopes, which were and continue to be spread throughout space by supernova explosions. Many isotopes are highly unstable and decay very rapidly, sometimes in a fraction of a nanosecond. These aren't found in nature anywhere on the globe. Only the most stable isotopes are remaining now.
In specially designed reactors, stellar-like nuclear conditions can be recreated. In this type of reactor, isotopes can be created, most typically through neutron bombardment. This is how we make the isotopes we use in research, medicine, and some industrial processes. The unstable (radioactive) isotopes produced will decay, producing another isotope or chain of isotopes until a stable (non-radioactive) isotope is reached.
Uses of Isotopes
There are many uses of isotopes across various industries. Let us look at a few of the uses of isotopes here.
Nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry are two analytical techniques commonly used in structural determination using isotopes (MS).
Nuclear Magnetic Resonance Spectroscopy
NMR analysis is isotope-dependent, and it frequently relies on the detection of trace isotopes of a molecule. For instance, the most abundant isotope of carbon, C-12, is NMR inactive, whereas the minor isotope C-13 is NMR active but only makes up 1.1 percent of a carbon sample. NMR measurement of that location is greatly achieved by replacing C-12 in a molecule with C-13. Similarly, because H-1 is an NMR active nucleus and H-2 is NMR invisible, substituting H-2 and watching for the signal to disappear can be used to determine the location of a single hydrogen atom.
Mass Spectrometry
The molecular weight of an ionised molecule and fragments of the molecule that appear when the molecule is ionised are determined using mass spectrometry. The measured mass of the parent ion—the charged molecule that does not fragment when an isotope is added. When an isotope is added, the observed mass of any fragment containing the isotope changes. The mass of a fragment will not change if it does not contain the isotope. This can reveal information about an isotope's position within a molecule.
Radioactive Isotopes
Any of several species of the same chemical element with differing masses whose nuclei are unstable and expend surplus energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays, also known as radioisotope, radionuclide, or radioactive nuclide.
Radioactive Isotopes Examples
The radioactive isotopes examples can be discussed here.
Radioactive isotopes can be used in a number of ways. Cobalt-60, for example, is widely used in medicine as a radiation source to halt the spread of cancer cells. Other radioactive isotopes are used as tracers in studies on metabolic processes and for research purposes.
When a small amount of a radioactive isotope is introduced to a large amount of a stable element, it acts chemically just like the ordinary isotope; however, it can be detected with a Geiger counter or other detecting device. Iodine-131 has been shown to be effective in the treatment of hyperthyroidism. Carbon-14, which is used in a breath test to detect the ulcer-causing bacteria Heliobacter pylori, is another medically important radioactive isotope.
Isotope Periodic Table
The isotope periodic table can be represented as follows:
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Element Isotopes Facts
Here are some interesting facts about isotopes.
The majority of elements found in nature are made up of several isotopes.
Nuclides is another name for isotopes.
There are now about 1000 unstable isotopes present. Some of these are found in nature, while others are produced in laboratories.
Only one stable isotope exists for nearly 20 elements. Gold, aluminium, phosphorus, fluorine, and sodium are only a few of them.
In fields such as carbon dating, nuclear reactors, and medicine, different isotopes of elements are used.
FAQs on Isotopes of Carbon Explained: Types, Examples & Uses
1. What are the main isotopes of carbon found in nature?
Carbon has three naturally occurring isotopes: Carbon-12 (¹²C), Carbon-13 (¹³C), and Carbon-14 (¹⁴C). Carbon-12 is the most abundant, making up about 98.9% of all carbon. Carbon-13 is also stable and accounts for about 1.1%, while Carbon-14 is a radioactive isotope present in trace amounts.
2. What is the fundamental difference between Carbon-12, Carbon-13, and Carbon-14?
The fundamental difference lies in the number of neutrons in their nucleus. All carbon isotopes have 6 protons, which defines them as carbon. However:
- Carbon-12 has 6 neutrons (6 protons + 6 neutrons = mass number 12).
- Carbon-13 has 7 neutrons (6 protons + 7 neutrons = mass number 13).
- Carbon-14 has 8 neutrons (6 protons + 8 neutrons = mass number 14).
3. What are some important real-world applications of carbon isotopes?
The different isotopes of carbon have unique and vital applications. For example:
- Carbon-14 is famous for its use in radiocarbon dating, a method to determine the age of ancient organic materials like fossils and archaeological artefacts.
- Carbon-13 is used in medical imaging and diagnostics, such as in the urea breath test to detect certain bacteria in the stomach.
- Carbon-12 serves as the international standard for defining the atomic mass unit (amu).
4. Why do carbon isotopes have nearly identical chemical properties but different physical properties?
This is because chemical properties are determined by an atom's electron configuration, which depends on the number of protons. Since all carbon isotopes have 6 protons, they have the same electron arrangement and react chemically in the same way. However, their physical properties, such as mass and nuclear stability, are determined by the nucleus (protons and neutrons). The difference in neutron count leads to different atomic masses and varying stability, with Carbon-14 being radioactive while Carbon-12 and Carbon-13 are stable.
5. How does the radioactivity of Carbon-14 work for carbon dating?
Living organisms constantly absorb carbon, including radioactive Carbon-14, from the atmosphere. When an organism dies, it stops taking in new carbon. The Carbon-14 within its remains begins to decay into Nitrogen-14 at a predictable, constant rate known as its half-life (approximately 5,730 years). By measuring the ratio of remaining Carbon-14 to stable Carbon-12 in a sample, scientists can calculate how long ago the organism died.
6. How is an isotope like Carbon-14 different from an isobar like Nitrogen-14?
The key difference is what stays the same.
- Isotopes are atoms of the same element with the same number of protons but a different number of neutrons (e.g., ¹²C and ¹⁴C both have 6 protons).
- Isobars are atoms of different elements that have the same mass number but a different number of protons. For example, Carbon-14 (6 protons, 8 neutrons) and Nitrogen-14 (7 protons, 7 neutrons) are isobars because they both have a mass number of 14.
7. Why is Carbon-12 the most abundant isotope of carbon in the universe?
The abundance of an isotope is linked to its nuclear stability. Carbon-12 has a nucleus with 6 protons and 6 neutrons. This even, balanced ratio of protons to neutrons creates a highly stable nucleus that does not undergo radioactive decay. Because of this exceptional stability, Carbon-12 has accumulated over billions of years and is energetically favoured, making it the most common form of carbon, accounting for over 98.9% of all carbon atoms.
