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:
1. Agree
2. Desagree
Explanation:
1. Americans chose loyalties based on geography, before starting civil war. Obviously, these alliances between states had an idology, which was intensified based on the region and the geographic position that they presented, therefore, alliances were created between southern states and northern states, which shared the same thoughts in relation to the slave system and the division of the national territory.
2. The Civil War did not end regional conflicts in America, on the contrary, the war created a strong disagreement and rejection of southern states in relation to northern states and vice versa. These conflicts have damaged social relations and reconstruction projects, in addition to delaying national unity.
Answer:what are the questions?
Explanation:
The Texas Revolution led to Mexico's cessession from the region of Texas, while Mexico's defeat in the Mexican American war forced Mexico to recognize Texas as an American State. Both of these events helped the US achieve Manifest Destiny but making it that much easier for the Country to reach from coast to coast, which was the "destiny" in question during the 19th century.