Arock contains 25 % of the parent isotope. the half-life of this isotope is 5 million years. calculate the age of the rock. for your answer, just type the age.

The age of the rock 10.00 million years old.

Explanation:

Half-life = 5 million years

First we have to calculate the rate constant, we use the formula :

Now we have to calculate the time passed.

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

where,

k = rate constant  =

t = time passed by the sample or age of the sample = ?

= let initial amount of the reactant  = x

N= amount left after decay process = 25% of x =0.25 x

The age of the rock 10.00 million years old.

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