system
Given the following post, respond as if you're commenting on Reddit:
human
If some elements have such a short half-life, why are they still here?

I'm not understanding something about radioactive decay, for example astatine has a half-life of between 5 and 10 hours depending on the specific isotope, yet it's naturally occurring. Why isn't all the Astatine in the world decayed into nothing?

Edit: Thanks so much for all the replies, I have learnt more in 15 minutes than I have over several days of googling!
gpt
An *element* doesn't have a half-life, each individual *isotope* of every element has its own half-life.

There are some radionuclides on Earth whose half-lives are much smaller than the age of the Earth, for example carbon-14.

It just means that these nuclides are being produced by some processes that happened after the birth of the solar system, and could still be ongoing.