A geologist estimates that a certain rock contained 12 mg of radioactive potassium-40 whe it formed.age of roc?

Note the assumptions in using radiometric dating:





The initial amount of each isotope is known.


The rate of decay has been constant.


There has been no contamination - adding or removing one of the isotopes.





All of these assumptions have been shown to be invalid in some circumstances.





More generally, much evidence for age is clearly faulty, and often involves radiometric dating. Rock from Mt St Helens volcano was dated as millions of years old when it is known to be just decades.


Diamonds contain carbon 14 when they 'shouldn't'.





Check out here for loads of articles on radiometric dating, and some of the pitfalls.


http://www.creationontheweb.com/content/鈥?/a>A geologist estimates that a certain rock contained 12 mg of radioactive potassium-40 whe it formed.age of roc?
Just two half-lives have passed. How do I know this? Because we have just 1/4 the original amount. So it's halved and halved again.