Half life radioactive dating definition
One way that helps scientists place fossils into the correct era on the Geologic Time Scale is by using radiometric dating.Also called absolute dating, scientists use the decay of radioactive elements within the fossils or the rocks around the fossils to determine the age of the organism that was preserved.
Perhaps you have heard of Ice Man, a man living in the Alps who died and was entombed in glacial ice until recently when the ice moved and melted.The man's body was recovered and pieces of tissue were studied for their C content by accelerator mass spectroscopy.The best estimate from this dating technique says the man lived between 33 BC. From the ratio, the time since the formation of the rock can be calculated.those that form during chemical reactions without breaking down).The unstable or more commonly known radioactive isotopes break down by radioactive decay into other isotopes.In other words, half (50%) of the Carbon-14 you started with has decayed into the daughter isotope Nitrogen-14.
However, your readout from your radioactivity measuring instrument says you have only 25% Carbon-14 and 75% Nitrogen-14, so your fossil must have been through more than one half-life.
This technique relies on the property of half-life.
Half-life is defined as the time it takes for one-half of a radioactive element to decay into a daughter isotope.
Below is a chart of commonly used radiometric isotopes, their half-lives, and the daughter isotopes they decay into.
Let's say you found a fossil you think to be a human skeleton.
Radioactive decay is a natural process and comes from the atomic nucleus becoming unstable and releasing bits and pieces.