system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what is radioactive decay?

I have been trying to identify what radioactive decay is, but everything on the internet makes it hard to comprehend. Can somebody tell me what it is in a simple way. thank you.
gpt
The nuclei of some atoms are not stable. They can become stable by undergoing radioactive decay where it releases certain particles (alpha, beta, etc.) and generally turns into a different atom. Sometimes elements have to undergo multiple decays in order to become stable.