Geologists rely on the Rule of Superposition to determine the age of geological structures. This rule assumes that no significant event took place and so older rock layers are positioned below the newer ones, similar to a stack of dirty dishes, where the newer ones are added on top and the older ones are further below.
Answer: 100 grams of the parent isotope will remain after one half life.
Explanation:
Mass of the isotope present at initial stage = 
The mass of the parent isotope left after the time ,t=N
Time taken by the samle ,t = 
The half life of the sample :


![\ln[N]=ln[N^o]-\frac{0.693}{t_{\frac{1}{2}}}\times t_{\frac{1}{2}}](https://tex.z-dn.net/?f=%5Cln%5BN%5D%3Dln%5BN%5Eo%5D-%5Cfrac%7B0.693%7D%7Bt_%7B%5Cfrac%7B1%7D%7B2%7D%7D%7D%5Ctimes%20t_%7B%5Cfrac%7B1%7D%7B2%7D%7D)
![2=\frac{[N_o]}{[N]}](https://tex.z-dn.net/?f=2%3D%5Cfrac%7B%5BN_o%5D%7D%7B%5BN%5D%7D)
![[N]=\frac{N_o}{2}=\frac{200 g}{2}=100 g](https://tex.z-dn.net/?f=%5BN%5D%3D%5Cfrac%7BN_o%7D%7B2%7D%3D%5Cfrac%7B200%20g%7D%7B2%7D%3D100%20g)
100 grams of the parent isotope will remain after one half life.
Mosses and ferns are seedless plants. They reproduce via the use of spores. The correct answer is C.
s would be secondary Explanation:
just cause