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.
I believe your answer is B, Because electrons are clinched to protons, most times, therefor there is not an electron microscope, but a ELECTRONIC Microscope will show the organism on a screen. hope that helped some<span />
Fossil fuels are considered a nonrenewable energy source because once fossil fuels are used, they are gone. So, the correct option is A.
<h3>What do you mean by Nonrenewable energy?</h3>
Nonrenewable energy may be defined as that energy that once consumed can not be replenished for millions of years.
Fossil fuels are examples of nonrenewable energy resources. The formation of fossil fuels may take over millions of years. This fuel is made naturally by the decomposition of dead and decayed organic living matter.
Therefore, the correct option for this question is A.
To learn more about Fossil fuels, refer to the link:
brainly.com/question/79954
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In meiosis the are two divisions. The division of the original cell results in two daughter cell. Those two cells divide to produce 4 haploid cell in total.
Answer:
Ecological importance
Healthy ecosystems depend on plant and animal species as their foundations. When a species becomes endangered, it is a sign that the ecosystem is slowly falling apart. Each species that is lost triggers the loss of other species within its ecosystem