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Radioactivity

Half-Life - Carbon Dating - Uses and Limitations.

Uses.

Carbon dating can be used on anything which used to be alive.
Examples are
1. Animal (or human) remains, including skin, fur and bone.
2.  Plant remains, including wood, natural fibres
(cotton, silk, wool, cloth, rope), seeds and pollen grains.

Some fossils can be dated this way
if they still contain some of the original carbon of the plant or animal.

Limitations.

Carbon dating cannot be used on things which have never lived.
Examples are brick, rock and metal.

The amount of carbon-14 in samples is very small and after 9 or 10 half-lives
 the amount of radioactivity which is emitted by the sample
is too tiny for an accurate count rate to be measured.
Therefore carbon dating cannot be used to date samples
which are more than 50,000 to 60,000 years old.

The method of carbon dating uses an assumption
that the amount of carbon-14 present in the past
is the same as that present in the environment today.

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