Potassium is an alkali metal with the chemical symbol K. It has an atomic number of 19, meaning that it has 19 positively charged protons. It also contains 19 electrons, which have a negative charge, and 20 neutrons, which do not hold a charge
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The answer is 0.008 moles
Answer: The age of the tool is 15539 years
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 = 100
a - x = amount left after decay process =
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.

b) for 15.5 % of original amount

Thus age of the tool is 15539 years