The rate at which they dissolve indicates the age of the fossil.
In very good circumstances, various radiometric techniques can be applied for the same stratum.
They point to a catastrophic origin for granites, consistent with the biblical timeframe for earth history and God’s judgment during the Flood.
A sample of igneous rock is found to contain the radioactive parent and daughter isotopes uranium, ^235U, and lead, ^207Pb, in the ration of 12.5%:87.5%.
Answer: 2.14 billion years old How did they get that?
I know the half life formula, which we did in math, but I guess the ratio part is confusing me. but am stuck as to how they get the number year value.
The "absolute" ages aren't strictly absolute, and allowance is made for uncertainty.