Answer: pH = 2,897 , basic![[H+][OH-] = 10^{-14} ==> [H+] = \frac{10^{-14}}{7,89*10^{-12} } =\frac{1}{789} \\pH= -lg([H+]) = 2,897 \\pH basic](https://tex.z-dn.net/?f=%5BH%2B%5D%5BOH-%5D%20%3D%2010%5E%7B-14%7D%20%3D%3D%3E%20%5BH%2B%5D%20%3D%20%5Cfrac%7B10%5E%7B-14%7D%7D%7B7%2C89%2A10%5E%7B-12%7D%20%7D%20%3D%5Cfrac%7B1%7D%7B789%7D%20%5C%5CpH%3D%20-lg%28%5BH%2B%5D%29%20%3D%202%2C897%20%5C%5CpH%3C7%20%3D%3D%3E%20basic)
Explanation:
Experiments suggest that organic molecules could have been synthesized in the atmosphere of early Earth and rained down into the oceans. RNA and DNA molecules — the genetic material for all life — are just long chains of simple nucleotides. Replicating molecules evolved and began to undergo natural selection.
Given, half life of a certain radioactive element = 800 years.
Amount of substance remaining at time t = 12.5%
Lets consider the initial amount of the radioactive substance = 100%
Using the half life equation:
A = A₀(1/2)^t/t₁/₂
where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.
Plugging the given data into the half life equation we have,
12.5 = 100 . (1/2)^t/800
12.5/100 = (1/2)^t/800
0.125 = (0.5)^t/800
(0.5)^3 = (0.5)^t/800
3 = t/800
t = 2400 years
Thus the object is 2400 years old.
c is the answer a benzene
