Stable trans-uranium elements?

[BigMoosie]

I heard that an isotope of element 114 would be stable, I can't recall which but it has not been proven. Are any other trans-uranium elements stable?

 

Tc and Pm are supposedly unstable, does this mean they do not appear in nature? If so why do we say there are 92 naturally occuring elements?

 

Also, how do you define naturally occuring, given time life will evolve from organic molecules until inelligence creates trans-uranium elements like we have done, if that all happens naturally, cant we say that they too are naturally occuring?

 

I have many questions on my mind today...

[swansont]

I heard that an isotope of element 114 would be stable' date=' I can't recall which but it has not been proven. Are any other trans-uranium elements stable?

 

Tc and Pm are supposedly unstable, does this mean they do not appear in nature? If so why do we say there are 92 naturally occuring elements?

 

Also, how do you define naturally occuring, given time life will evolve from organic molecules until inelligence creates trans-uranium elements like we have done, if that all happens naturally, cant we say that they too are naturally occuring?

 

I have many questions on my mind today...[/quote']

 

note that stable <> naturally occurring

 

Naturally occurring is basically what it says - you can dig it up somewhere in nature. Tc and Pm are not naturally occurring because they aren't produced in a decay chain, unlike the elements heavier than Bi out to U.

 

And "we" don't say that there are 92 naturally occurring elements.

[Meir Achuz]

"stable" and "unstable" sometimes have to be quallified.

All elements above Pb are unstable, sometimes with very long lifetimes.

Often, when talking about these heavier elements, they are not called "unstable" if they have long enough lifetime. ("Enough" depends on the circumstances.)

For instance, U238, with a lifetime over 10^9 years is often called stable, and only rarely called unstable. Some transuranium elements have long lifetimes.

Plutonium 244 has a lifetime of about 10^8 years, which is too stable for safety.