[Borek]

I was - all the time - putting nucleus problems on side. Perhaps half of the discussion should be preceded by "Assuming there are no stability problems with heavy elements, how are electrons going to fill up the shells?"

[Oldtimer]

Considering the properties of elements that don't even exist anywhere we can actually find them is not really neccessary anyhow. What would we do with element 122?

We can't even work with uranium much the way things are here on Earth.

[jdurg]

Well once the nucleus has enough protons to exert a pull on the 1s electron requiring the 1s electron to move FASTER than the speed of light, then the limit is reached because nothing can move faster than the speed of light.


EDIT:  Based on some very huge assumptions and very rough calculations, you'd need an atomic number of 9400 for the nucleus to have enough positive charge to force the electron to travel at the speed of light to remain outside the nucleus.  YIKES!

[Borek]

Well once the nucleus has enough protons to exert a pull on the 1s electron requiring the 1s electron to move FASTER than the speed of light, then the limit is reached because nothing can move faster than the speed of light.

No such limit.

m_v= m/sqrt(1+v²/c²)

[jdurg]

No such limit.

m_v= m/sqrt(1+v²/c²)

Shouldn't that be the square root of (1-v²/c²)?  I have NEVER seen the equation where it's 1+.  It's always been 1- because it's stating that you cannot move faster than the speed of light, or even at the speed of light, because then that equation would have no answer to it as you cannot get a square root 0 or a negative number.

[Borek]

Shouldn't that be the square root of (1-v²/c²)?

Typo

But still no such limit

[jdurg]

Yeah there is a limit.  You cannot take the square root of zero or a negative number.  Any time your velocity is equal to the speed of light or is greater, that equation cannot be solved.  

[jdurg]

Either way, I cannot fathom an atom with a nucleus which weighs over 9400 amu.    Those atoms would be so big that a mole would probably weigh close to a metric ton.  lol.

[Oldtimer]

If the nucleus is Axial, then what are the interior electrons doing? Is the 1s pair just trapped in the center of the nucleus, unable to move away or any closer?

This may not be appropriate, but I think of a donut magnet when picturing the nucleus. Throw some iron filings in the area and they are visually differing from the orbits or flux flow of a single button magnet. the filings would draw into the center heavily. but the filings aren't up to the task of competing as an electron would. And certainly don't have the velocity or spin to help.

But they also will leave some filings in stasis directly in the center of the donut. Indicating to me at least that the 1s orientation would be along the axis of the 'donut hole', the 2 s then being an enormous longitudinal orientation with fat exterior wave. And the 2p orbital would be similarly a huge latitudinal system.

This is the only link I can find.
http://jeries.rihani.com/

Andy

[Borek]

Yeah there is a limit.  You cannot take the square root of zero or a negative number.  Any time your velocity is equal to the speed of light or is greater, that equation cannot be solved.

No. Electron can take ANY energy, regardless of how high, without the need of reaching light speed. And I can take a square root of zero - you can't?

[jdurg]

No. Electron can take ANY energy, regardless of how high, without the need of reaching light speed. And I can take a square root of zero - you can't?

My bad.  I meant divide by zero.  So sure you can get the square root of zero, but try solving your equation now with m/0.  

I'm sorry, but nothing can travel faster than the speed of light.  It just can't happen.

[Borek]

I'm sorry, but nothing can travel faster than the speed of light.  It just can't happen.

The problem is, I don't understand where do you see a need for speed higher then c. Can you explain?

[jdurg]

The problem is, I don't understand where do you see a need for speed higher then c. Can you explain?

Me thinks that there is just a slight little misunderstanding going on.  

My discussion is on the 1s electrons in a big, heavy atom.  The 1s electron is closer to the nucleus than any other electron in an atom.  Therefore, in the heavier atoms those electrons feel a MUCH stronger pull from the higher positive charge of the nucleus than they do in a lighter atom.  I believe that the distance between the nucleus and the 1s subshell is pretty consistant amongst the elements.  Therefore, as you move up in the periodic table those 1s electrons would have to be zipping around a bit faster in order to prevent themselves from getting sucked into the nucleus, correct?

Since the majority of the electron's energy comes from its movement, if the electron slows down it gets pulled further towards the nucleus.  I'm just stating that there will come a point where the nucleus will have such a high positive charge that the electron will simply not be able to stay out of the nucleus.  It won't be able to move fast enough to prevent itself from being sucked into the high positive charge of the nucleus.  That's where the whole 'speed of light' concept came into play.  I was stating that once the nucleus gets big enough (my incredibly rough and likely erroneous value of 9400 protons), the electron would have to move faster than the speed of light in order to have enough energy to remain outside of the nucleus.  Since the speed of light cannot be eclipsed, that can't happen and that would be the limit.  Kind of get what I'm stating here?  (I still think we've just misinterpreted each other somewhere.   )

[Mitch]

Considering the properties of elements that don't even exist anywhere we can actually find them is not really neccessary anyhow. What would we do with element 122?

We can't even work with uranium much the way things are here on Earth.

How can you be a chemist and not want to know the chemistry of a new element?

Jdurg: There are elements above 9800amu, they are called neutron stars. But, there is a huge gap in between neutron stars and 9400amu.

[Borek]

Me thinks that there is just a slight little misunderstanding going on.

Not for the first time, not for the last time As long as we want to clarify situation, that's not the problem

My discussion is on the 1s electrons in a big, heavy atom.  The 1s electron is closer to the nucleus than any other electron in an atom.  Therefore, in the heavier atoms those electrons feel a MUCH stronger pull from the higher positive charge of the nucleus than they do in a lighter atom.

I suppose you were referring to the planetary model, which - since Schroedinger - is of no use?

I believe that the distance between the nucleus and the 1s subshell is pretty consistant amongst the elements.

It is not.

Wave function for the 1s takes form N_1sexp(-Zr/a₀) - N_1s is normalization constant, a₀ is a radius of first Bohr orbit and is sometimes used as length unit in quantum chemistry.

Note, that the shape of the function is dependent on the nucleus charge, thus the higher the charge, the closer the maximum electron density is to the nucleus.

Therefore, as you move up in the periodic table those 1s electrons would have to be zipping around a bit faster in order to prevent themselves from getting sucked into the nucleus, correct?

In terms of planetary model, yes. But that's one of the reasons that planetary model is no longer used

Since the majority of the electron's energy comes from its movement, if the electron slows down it gets pulled further towards the nucleus.

Once again - in terms of planetary model only. IIRC speed of the electron on the orbitals is constant and has something to do with subtle structure constant (? no idea how it is called in English). But at the same time speed of the electron is not a thing that makes sense in the case of orbitals, as electron on the orbital doesn't behave like a particle. Thus all analogies with planetary systems are wrong.

I'm just stating that there will come a point where the nucleus will have such a high positive charge that the electron will simply not be able to stay out of the nucleus.  It won't be able to move fast enough to prevent itself from being sucked into the high positive charge of the nucleus.  That's where the whole 'speed of light' concept came into play.  I was stating that once the nucleus gets big enough (my incredibly rough and likely erroneous value of 9400 protons), the electron would have to move faster than the speed of light in order to have enough energy to remain outside of the nucleus.  Since the speed of light cannot be eclipsed, that can't happen and that would be the limit.  Kind of get what I'm stating here?  (I still think we've just misinterpreted each other somewhere.   )

OK, I understand your point, but as I explained above it is wrong. I don't think I will be able to explain it better - I was never good in quantum chemistry and I have passed last exam on the subject in February 1983 so my knowledge in the area holds mostly on rust and may fall down when touched

I was all the time under impression that you are referring to the fact that low orbits in heavy atoms are of high energy (which is true) and that the electron to have such high energy will have to move faster then light (which is not true).