Why are Heavy Elements Still Here?

Most recent answer: 12/15/2012

Q:
If all elements have a half-life, and all the heavy elements were created from the "big bang" which happened 14 billion years ago, why haven't all these elements disappeared if they keep losing 1/2 of their make-up. Shouldn't all of these elements, which were all created at the same time, or shortly, relatively speaking, after the "big bang", have disappeared? Why/how are they still here?
- Richard (age 61)
Lawrenceville, Georgia USA
A:
Actually, the elements heavier than lithium have all been made more recently, either in regular stars or in supernova explosions. Still, there are lots of elements left for billions of years.

The main reason that they're still here is very simple. Some have enormous half-lives.(Check this list: .) So they're still around. Others have somewhat shorter half-lives but are produced in the decays of ones with longer half-lives. So they're being made continuously.

(published on 12/15/2012)