Answer:
d. Obsessive-Compulsive Disorder
Explanation:
Obsessive-Compulsive Disorder or OCD is an anxiety disorder in which people have perpetual unpleasant thoughts that fully occupy them and lead to a need to repeat different action multiple times. For instance washing hands. That affects their life a lot and productivity, also mental state as they are anxious that they didn't do something good enough which cause doing numerous checkings in order to be sure that the specific thing is done. In the given situation, Chuan has OCD which leads to constantly going back to the first ten questions and checking if he marked them right. Also there is a consequence - he didn't have time to complete the whole test.
Answer:
The rock is 3.75 billion years ago.
Explanation:
Given that:
Half life = 1.25 billion years
1 billion years = 10⁹ years
So,
Half life = 1.25 × 10⁹ years

Where, k is rate constant
So,


The rate constant, k = 5.5452 × 10⁻¹⁰ years⁻¹
Initial amount [A₀] = 80 micrograms
Final amount
= 10 micrograms
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
So,





So,
<u>The rock is 3.75 billion years ago.</u>
Answer:
<h2>B. </h2><h3>how to use the phone
</h3>
Explanation:
I hope this helps
Substance abuse would be the answer. Hope this helps.