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.
A clade is a group of species that includes an ancestral species and all of its descendents
<span>Here are some advantages:
1. it can create new varieties of good crops.
2. it allows for higher profit.
3. it does not have a issue of safety.
4. it helps eliminate diseases
5. it can produce fitter and stronger animals
Here are some disadvantages:
1. it can lead to a loss of species variety
2. it doesn't have control over genetic mutations
3. it brings discomfort to animals
4. it can create offspring with different traits
5. it poses some environmental risks</span>
Two things that Characterize the practice of science is empirical evidence and community consensus. Hope this helps.