Radioactive isotope dating fossils ask dating during question speed
Radioactive isotope dating fossils
Many rocks and organisms contain radioactive isotopes, such as U-235 and C-14.
These radioactive isotopes are unstable, decaying over time at a predictable rate.
Familiar to us as the black substance in charred wood, as diamonds, and the graphite in “lead” pencils, carbon comes in several forms, or isotopes.
One rare form has atoms that are 14 times as heavy as hydrogen atoms: carbon-14, or C ratio gets smaller.
The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.