Answer:
d. Can be replaced at the same rate or faster than they are used
Explanation:
I just took the test, and its the right answer. Your welcome ✌
<h2>A is the correct answer!</h2><h3></h3><h3>I'm too lazy to explain :(</h3><h3></h3><h3><em>Please let me know if I am wrong.</em></h3>
Answer:
- 0.09 % of the original radioactive nucllde its left after 10 half-lives
- It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Explanation:
The equation for radioactive decay its:
,
where N(t) its quantity of material at time t,
its the initial quantity of material and
its the mean lifetime of the radioactive element.
The half-life
its the time at which the quantity of material its the half of the initial value, so, we can find:

so:




So, after 10 half-lives, we got:




So, we got that a 0.09 % of the original radioactive nucllde its left.
Putonioum-239 has a half-life of 24,110 years. So, 10 half-life will take to pass

It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Answer:
because our some of the energy goes from our eyes
explanation;
There are several reasons why it's important to close our eyes while we sleep. Closed eyelids block light, which stimulates the brain to wakefulness. Closing our eyes also protects and lubricates the eyes while we sleep