RADIOCARBON
DATING - SCI & TECH
News:
What is radiocarbon
dating? | Explained
What's
in the news?
●
Radiocarbon dating brought the first
verifiable way to keep time to many fields of science, significantly
transforming them.
Carbon
Dating:
●
Carbon dating is a widely-used method to
establish the age of organic materials,
things that were once living.
●
Living things have carbon in them in
various forms.
Carbon-14
(C-14):
●
The dating method is based on the fact
that Carbon-14 (C-14), an isotope of
carbon with an atomic mass of 14, is radioactive, and decays at a well-known
rate.
●
The most abundant isotope of carbon in the
atmosphere is C-12.
●
The ratio of C-12 to C-14 in the
atmosphere is almost static, and is known.
○
Plants and animals acquire C-12 and C-14
in roughly the same proportion as is available in the atmosphere.
●
When they die, their interactions with the
atmosphere stop.
Half-life
of C-14:
●
While C-12 is stable, the radioactive C-14
reduces to one half of itself in about
5,730 years — known as its ‘half-life’.
Significance
of Radiocarbon Dating:
●
The changing ratio of C-12 to C-14 in the
remains of a plant or animal after it dies can be measured, and can be used to
deduce the approximate time when the organism died.
Drawbacks
of Radiocarbon Dating:
●
Carbon dating cannot be used to determine
the age of non-living things like rocks.
●
The age of things that are more than
40,000-50,000 years old cannot be arrived at through carbon dating.
Go
back to basics:
Radiometric
dating methods:
1.
Potassium-argon dating:
●
The radioactive isotope of potassium
decays into argon and their ratios can give a clue about the age of rocks.
2.
Uranium-thorium-lead dating:
●
Uranium and thorium have several
radioactive isotopes and all of them decay into the stable lead atom. The
ratios of these elements present in the material can be measured and used to
make estimates about age.
3.
Cosmogenic nuclide dating:
●
It is used to determine how long an object
has remained exposed to sunlight. It is regularly applied to study the age of
ice cores in polar regions.