With an extra neutron and one less proton, that's no longer a nitrogen atom — six protons plus eight neutrons spells carbon-14.
The newly formed carbon-14 atoms end up in carbon dioxide, which ends up in plants, which end up on our dinner plates as fruit, veg or a highly processed version of plants known as meat.
And after 11,460 years (two half-lives), only a quarter of the original carbon-14 atoms are left.
After five half-lives (28,650 years) only 1/32 remains.
It's not that the radioactive carbon in air or food doesn't decay, it does.
Luckily for us we have a record of atmospheric carbon-14 levels for every one of the last 12,000 years.For a rare event it happens pretty damn often — one million carbon-14 atoms in your body decay into nitrogen every minute!But don't panic — of the 800,000,000,000,000,000,000,000,000 carbon atoms in every one of us, about 800,000,000,000,000 are carbon-14, so we've got a few to spare.And that something else starts where Earth meets space.Earth's upper atmosphere is constantly being bombarded by cosmic rays (usually protons travelling at nearly the speed of light).