Context:
Article in the Hindu – What is radiocarbon dating? | Explained
About Radiocarbon dating:
- ‘Dating’ is a technique used to determine the age of an object.
- Radiocarbon dating is a technique that utilizes carbon-14, an isotope of carbon, to determine the age of an object.
- According to the American Chemical Society, “radiocarbon dating provided the first objective dating method – the ability to attach approximate numerical dates to organic remains”.
Radiocarbon dating helped establish the age and authenticity of the famous Dead Sea Scrolls.
How did Carbon-14 form in the earth’s atmosphere and reach living organisms?
- Carbon-14 originates in the Earth’s atmosphere through the impact of cosmic rays, which are energetic charged particles from outer space, colliding with gas atoms and releasing neutrons.
- When these neutrons interact with the nitrogen-14 isotope, carbon-14 is produced.
- Due to the continuous influx of cosmic rays into the Earth’s atmosphere, carbon-14 is consistently generated.
- The newly formed carbon-14 easily combines with atmospheric oxygen, resulting in the formation of radioactive carbon dioxide.
- This compound then becomes integrated into the bodies of plants (through photosynthesis), animals (via the consumption of plants), and other biomass as part of the carbon cycle.
How does radiocarbon dating work?
- When an organic entity, such as the human body, is ‘alive,’ it undergoes a continual exchange of carbon with its environment through processes like breathing, food consumption, defecation, skin shedding, etc.
- During these activities, carbon-14 is both released from and replenished in the body, maintaining a nearly constant concentration in equilibrium with the surroundings.
- Upon the individual’s death, these life processes cease, leading to a decline in the concentration of carbon-14 within the body due to radioactive decay.
- As time elapses, the amount of carbon-14 diminishes, and the decay rate follows a predictable pattern based on theoretical principles.
- Radiocarbon dating determines the age of an object by measuring the remaining amount of carbon-14, which scientists or computers can then use to calculate the time since the organism’s death.
Tools of radiocarbon dating
- Geiger counter
- Accelerator Mass Spectrometry (AMS)
Source: The Hindu
Previous year question
In the context of recent advances of human reproductive technology, “Pronuclear Transfer” is used for
(a) fertilization of egg in vitro by the donor sperm
(b) genetic modification of sperm producing cells
(c) development of stem cells into functional embryos
(d) prevention of mitochondrial diseases in offspring
Answer: d
