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
Answer:
this is a required answer. look it once.
Noice but I don’t get why was this necessary
Im pretty positive its A , hope this helps!
Answer : Hypothesis.
Explanation : Hypothesis is defined as the supposition or proposed explanation which can be made on the basis of limited available evidence as a starting point for further investigation. Here, in this question the proposed explanation for the changing colors of the sky is an example of a hypothesis.
A hypothesis has to be supported with scientific experiments which are reproducible by several experiments and test results have to be valid to be called as a scientific theory.