system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If radioactive elements decay over time, and after turning into other radioactive elements one day turn into a stable element (e.g. Uranium -> Radium -> Radon -> Polonium -> Lead): Does this mean one day there will be no radioactive elements left on earth?
gpt
Perhaps we could run out of uranium one day, but some radioactive elements like carbon-14 are constantly replenished by cosmic rays, and others like bismuth-209 have long enough half-lives to outlast the Earth by a wide margin.