Answer: The answer is both I believe. :)
Explanation:
The answer is D. (Russia)
Answer:
After three half-lives, it is 7:1
Explanation:
- The rate at which the decay of the radioactive isotope is said to be half-life and is represented as the half-life of the atoms and the matter to disintegrate itself.
- The two radioactive isotopes are K 40 and Ar 40. After the K-Ar dating, they contain minerals such as the clay mica and the temphra minerals and Half-life of the K 40 is 1.3 more than 100,000 years i.e 10x9 years for Ar 40.
- <u>Thus the K 40 has to divide as three half-lives have passed if the ratio of argon to potassium atoms is 7:1. At the end of one half-life, the ratio of the number of argon to potassium atoms is 1:1. and two half lives its 3:1 thus after the third half-life it becomes as 7:1.</u>
The atmosphere<span> also protects living things on </span>Earth<span> from the sun's harmful ultraviolet radiation. A thin layer of gas called ozone high up in the </span>atmosphere<span> filters out these dangerous rays. The </span>atmosphere<span> also helps to sustain life of </span>Earth<span>.</span>
It protects the coast from the raw ocean, it cuts waves off, and depending on how big the island is, could stop a tsunami
