Answer: 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.
The flooding of half part of the forest have successful separate the population of frogs in that ecosystem into two different set of frogs. This is an example of allopatric speciation, that is, the population become separated as a result of geographical barrier. This separation will make the two set of frog population to become new species. On the long run, the two species may become unable to relate sexually.
This is most definitely the definition for a Lipid!
its true............................................true
The answer to this question is Condensation