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Carbon Dating and Archaeological Specimens.

What are Archaeological Specimens?

Archaeological specimens are things which belonged to
people in the past and have been dug up from the ground.
Archaeological is pronounced ar-key-o-logical.

Why are Archaeological Specimens Important?

The study of archaeological specimens can tell you a lot
how people in the past lived. One of the most important
things to know is the age of the object. This tells you how
long ago
the thing was used or how long ago the thing was living.

How is Carbon Dating used to Date Archaeological Specimens?

The half-life of carbon-14 is 5,730 years. The half-life can be
used to calculate the age of a sample containing carbon-14.
Carbon dating is very useful but also has its limitations.

If a specimen sample had an amount of carbon-14 which was 25%
of the amount in today's environment, how old would the sample be?

Find how many half-lives
would be needed to reduce the amount of carbon-14 to 25%.

Calculate Half-life using Carbon Dating

After 2 half-lives the amount of carbon-14 is reduced to 25%.

The sample is 2 x 5,730 years old
= 11,460 years old.

If the amount of carbon-14 in the sample was only 6·25%,
then the sample would be 4 half-lives old.
4 half-lives are 4 x 5,730 years = 22,920 years old.

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