C 14 carbon dating
Radiocarbon then enters animals as they consume the plants (Figure 1b).
So even we humans are radioactive because of trace amounts of radiocarbon in our bodies.
Many people assume that rocks are dated at “millions of years” based on radiocarbon (carbon-14) dating. The most well-known of all the radiometric dating methods is radiocarbon dating.
Carbon-14 can yield dates of only “thousands of years” before it all breaks down.
The radiocarbon half-life or decay rate has been determined at 5,730 years.
Next comes the question of how scientists use this knowledge to date things.
The standard way of expressing the decay rate is called the half-life.5 It’s defined as the time it takes half a given quantity of a radioactive element to decay.
Let’s suppose we find a mammoth’s skull and we want to date it to determine how long ago it lived.By comparing the surviving amount of carbon-14 to the original amount, scientists can calculate how long ago the animal died.Since the atmosphere is composed of about 78% nitrogen,2 a lot of radiocarbon atoms are produced—in total about 16.5 pounds (7.5 kg) per year.Radioactive and non-radioactive carbon dioxide mix throughout the atmosphere, and dissolve into the oceans.Through photosynthesis carbon dioxide enters plants and algae, bringing radiocarbon into the food chain.