In modern texts and in Earth system science, geosphere<span> refers to the solid </span>parts<span> of the Earth; it is used along with atmosphere, hydrosphere, and biosphere to describe the systems of the Earth.</span>
Has varied greatly over time
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.
Answer:
Valley lizard = Oviparous
Mountain lizard = Viviparous
Explanation:
In Darwin's theory survival of the fittest, he believed species adapt or change within their environment. So I believe lizards living in a valley would be more safe to lay their eggs but lizards living in the mountains would be viviparous because of the non-predicted and unsafe environment which could harm the better chances of development of the offspring.