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:
wait 2minutes I will give you answer
Answer:
The president has the power to make treaties, with a two-thirds vote of the Senate, and has the power to make international agreements. ... The president can also influence foreign policy by appointing US diplomats and foreign aid workers.
Explanation:
Answer:
D). The mirror is a symbol of the need for self-reflection and a commitment to improving the world.
Explanation:
Symbols are meant to signify a more deeper meaning associated/presented to a common or simple thing or object.
As per the question, the mirror as a symbol could best be explained through option D as it represents a deeper symbolic meaning attached to the common object 'mirror'. <em>It portrays the mirror 'as a symbol of the need of self-reflection and a sort of commitment to improve or uplift' the world'.</em> Thus, <u>option D</u> is the correct answer.