# Half life and carbon 14 dating

CARBON-14 IS ABSORBED (Figure 1b): Plants absorb this carbon-14 during photosynthesis.The most widely used tool to measure the age of the Earth is radioactive decay.CARBON-14 IS CREATED (Figure 1a): When cosmic rays bombard the earth’s atmosphere, they produce neutrons.These excited neutrons then collide with nitrogen atoms in the atmosphere, changing them into radioactive carbon-14 atoms.An essential characteristic of exponential functions is that their values change by equal factors over equal intervals, that is, if $f(x)$ is an exponential function and $b$ a fixed real number, then the quotient $$\frac$$ always takes the same value, that is, it does not depend on the real number $x_0$.This exploratory task requires the student to use this property of exponential functions in order to estimate how much Carbon 14 remains in a preserved plant after different amounts of time.

It takes a certain amount of time for half the atoms in a sample to decay.

This has to do with figuring out the age of ancient things.

If you could watch a single atom of a radioactive isotope, U-238, for example, you wouldn’t be able to predict when that particular atom might decay.

Scientists look at half-life decay rates of radioactive isotopes to estimate when a particular atom might decay.

A useful application of half-lives is radioactive dating.