What Carbon-14 has a half-life of nearly 6000 years. If one half-life (50 %) of the original carbon-14 is left in a material, how old is it?
Well, the material is
An element's nuclear half-life is used to determine how much time will it take for half of the atoms in an original sample to undergo radioactive decay.
So, in this case, it will take 6000 years for 50% of carbon-14 atoms in that respective material to undergo radioactive decay. If 50% of the atoms undergo decay, that means that 50% of the original sample remains after one half-life.
In another 6000 years, the number of carbon-14 atoms will be equal to 25% of the original sample, in another 6000 years, to 12.5% of the original sample, and so on.