Wood deposits recovered from an archaeological site contain 36% of the C-14 they originally contained. How long ago did the tree from which the wood was obtained die?

It was obtained 8515 years ago

Explanation:

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) to find the rate constant:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

b) for completion of 36% of reaction

t = 8515 years

The time was 8515 years.

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