rapidsvn error error while updating filelist options - Radiometric dating calculator uranium
As long as an organism is alive, the amount of C-14 in its cellular structure remains constant.But when the organism dies, the amount of C-14 begins to decrease.
It might take a millisecond, or it might take a century. But if you have a large enough sample, a pattern begins to emerge.
It takes a certain amount of time for half the atoms in a sample to decay.
Of all the isotopic dating methods in use today, the uranium-lead method is the oldest and, when done carefully, the most reliable.
Unlike any other method, uranium-lead has a natural cross-check built into it that shows when nature has tampered with the evidence.
Uranium comes in two common isotopes with atomic weights of 235 and 238 (we'll call them 235U and 238U).