Personal question about periodic table

[Banks]

So we know that periodic table is 143 years old, and I wonder -

 

Have we run out of elements that we have already discovered on this planet earth?

 

What is the periodic table going to look like in 500 years from now on?

 

Are the new elements going to be added to our periodic table when we visit other planets?

[Santalum]

So we know that periodic table is 143 years old, and I wonder -

 

Have we run out of elements that we have already discovered on this planet earth?

 

What is the periodic table going to look like in 500 years from now on?

 

Are the new elements going to be added to our periodic table when we visit other planets?

 

Unless our theories about the structure and nature of the atom is fundamentally wrong (unlikely) then the periodic table of today will be identical to the periodic table of 500 years from now.

 

All the places in the periodic table, atomic number 1 to 96 that correspond to naturally occuring stable elements, are filled and all the possible elements have been discovered.

 

There can be no new ones other than artificial elements created in nuclear reactors and that can only exist for fractions of a second before they spontaneously fall apart beyond atomic number 96.

 

Or is it 95......what ever.

[Schrödinger's hat]

To elaborate slightly on what Banks said:

We do slowly add elements to the periodic table. As we smash together larger and larger nuclei, sometimes we manage to get a large nucleus to stick around long enough to do some measurements on it.

To give you an example, one of the most recent additions (the most recent addition?) to be officially recognised is Copernicium (number 112).

These elements are generally far too short lived to be found in nature (with half-lives between milliseconds and seconds).

There are some predictions that some of the heavier elements still to be discovered will be more stable (between seconds and days, still not stable enough to find in nature unless you were very carefully picking through the remnants of a very recent supernova).

 

The only possible use I can think of for some of these ultra-heavy elements is if you want a portable source of very specific energies of radiation. I can think of no good reason as to why you'd want this. Maybe for some kind of medical imaging? They would also be inferior in many ways to most currently used (natural and synthetic) elements used for this purpose due to very short shelf life and difficulty of production.

 

TL;DR version:

Yes, we've run out of elements that can be found in nature (be it on earth, stars or other planets). With the possible exception of finding the tiniest trace amounts of some of the elements we've already made in the lab (but not found in nature).

It'll look much the same, maybe with an extra line or two on the bottom which anyone except nuclear physicists will leave off/ignore due to them being too radioactive to ever be useful.

No, other planets will be made of the same stuff as Earth.

[mississippichem]

Chemistry ceases to be interesting somewhere around astatine, radon or francium. IIRC some people have prepared AtH in small quantities but who cares really ?

Edited February 15, 2012 by mississippichem

[Schrödinger's hat]

Chemistry ceases to be interesting somewhere around astatine, radon or francium. IIRC some people have prepared AtH in small quantities but who cares really ?

 

No love for thorium and uranium?

[mississippichem]

No love for thorium and uranium?

 

There is certainly some interesting actinoid chemistry. They are strange though and pretty much all we know about their chemistry is a collection of empirical facts. Physical chemistry people tend to hate them as they usually lead to computational nightmares.

 

Those deeply buried l=3 orbitals do weird stuff. Relativistic methods also become important in those large nuclei.

Edited February 15, 2012 by mississippichem

[John Cuthber]

A lot of uranium compounds are nice colours and look pretty under UV light.

 

It is still hypothetically possible that some heavier elements are relatively stable. But the definition of " relatively stable" doesn't mean you will find them in the chemicals supplier's catalogues.

[mississippichem]

A lot of uranium compounds are nice colours and look pretty under UV light.

 

It is still hypothetically possible that some heavier elements are relatively stable. But the definition of " relatively stable" doesn't mean you will find them in the chemicals supplier's catalogues.

 

I must admit I do have a few uranium [oxide?] glass spheres that are fun to play with under a TLC UV hand bulb.