In an atom, the maximum number of electrons that each orbit can hold are 2, 8, 18, 32, 32, 18, 8, 2. The sum of all these numbers equal to 120. So what would the electron configuration for elements after the 120th be?

I say 111 confirmed and 118 claimed elements.

I say 111 confirmed and 118 claimed elements

I thought about the same.

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Is that the configuration for Mercury above?
http://education.jlab.org/qa/electron_config.html defines it as

Energy Level
(Principal Quantum N#)   Shell Letter   Electron Capacity
1                           K                          2
2                           L                           8
3                           M                         18
4                           N                         32
5                           O                         50
6                           P                         72


Wikopedia states :
Aufbau principle

In the ground state of an atom (the condition in which it is ordinarily found), the electron configuration generally follows Aufbau principle. According to this principle, electrons enter into states in order of the states' increasing energy; i.e., the first electron goes into the lowest-energy state, the second into the next lowest, and so on. The order in which the states are filled is as follows:
   s    p    d    f    g
1      1
2      2    3
3      4    5    7
4      6    8    10    13
5      9    11    14    17    21
6      12    15    18    22
7      16    19    23
8      20    24

A pair of electrons with identical spins has slightly more energy than a pair of electrons with opposite spins. Since two electrons in the same orbital must have opposite spins, this causes electrons to prefer to occupy different orbitals. This preference manifests itself if a subshell with l > 0 (one that contains more than one orbital) is less than full. For instance, if a p subshell contains four electrons, two electrons will be forced to occupy one orbital, but the other two electrons will occupy both of the other orbitals, and their spins will be equal. This phenomenon is called Hund's rule.

The Aufbau principle can be applied, in a modified form, to the protons and neutrons in the atomic nucleus (see the shell model of nuclear physics).

Andy

Do you understand the difference between the two? See it in your mind as lower energy rings as you move away from the nucleus. 1, 2, 3, 4, 5, 6, 7, and 8th orbits away each one a lesser strength as you move away further and further. The energy holding the outer electrons to the atom are very weak in the larger {Radioactive} elements.

The s, p, d, f, and g are in reference to geometric orientations of the prefered filling order of EACH orbit number.  This has to do with gamma, beta, and alpha orientation in bond linkages. so if you aren't going to be discussing that in your class - don't worry about that just yet.

Do they repeat. Yes. The orbits have to be balanced and they balance by filling these orbits in order.

These orbits aren't circular {at least in the lowere s,p,d}, think figure eights instead. Now you are beginning to view how the geometry and bonds will occur from atom to atom in a preferred alignment manner.

Okay? They repeat this filling system for EACH orbit level of 1{K}, 2{L}, 3{M}, 4{N}, 5{O}, 6{P}, and possibly extra orbits of 7 and 8 if these extra  elements are proven to exist in any natural state at any magnetic or gravimetric sustainable condition. Of course not each atom will have the same upper filled shells, thus their individual difference in chemical and physical properties..

http://www.webelements.com/webelements/elements/text/periodic-table/econ.html

The existance of some of these orbits will interfere with lower level filled geometries in large atoms. Dropping at least  the p and d most likely in unknown large atoms.

Do you understand that, or should I/we try again? this is not an easy topic beyond this level. The Physicists are arguing about the actual configuration in some circles of many common elements and compounds. Stereochemistry is not a simple subject matter either. don't feel bad if you are confused, just ry to explain your issue. Maybe I'm guessing your point of confusion wrongly.
Andy

Though I'm not sure if this will help or hinder you, one must also remember that the orbitals are NOT physical objects.  They are just regions in space.  If you could look at an atom, you wouldn't see these orbitals in their geometric shapes.  The only things you'd see are the nucleus and an occasional electron whipping around.  Eventually there will come a point where you simply cannot add any more electrons to an atom as there will simply not be enough space around an individual nucleus to fit all those electrons.  While the positive charge of the nucleus may be large, the shear number of electrons around the nucleus will make the outer electrons feel almost no pull.  So I'm not sure what the number is, but I do believe in theory that there is some limit as to how high of an atomic number a neutrally charged atom can exist.

While the positive charge of the nucleus may be large, the shear number of electrons around the nucleus will make the outer electrons feel almost no pull.  So I'm not sure what the number is, but I do believe in theory that there is some limit as to how high of an atomic number a neutrally charged atom can exist.

That's an interesting approach, but I think it is slightly wrong.

Assume you have a single atom that has n charged nucleus, and there are n-1 electrons on the orbitals.

If you look at the atom from the distance it has a +1 charge, so it will always pull an additional electron. If you are far enough it doesn't matter what is inside, that's the Gauss's law.

However, you are right that the valence electron will be far from the nucleus, so the force attracting it will be much smaller. Thus I think correct approach is that there is no limit on the size of neutrally charged atom, just the first and subsequent ionization energies will be smaller and smaller.

I believe the physics majors will disagree with our opinion though. It doesn't fit the previous chapters they've mastered.

Yet the planetary chemists {such as jdurg?} will know that gravity of other worlds will exert greater magnetic influence on the elements in their environment. suppose if the gravity of say Jupiter is so great that naturally occuring elements there means they are all heavy isotopes instead of our versions. What would that do to our periodic table?

The probability that super heavy elements don't have an s ,p, or d orbital I also feel is likely because of radioactive decay destroying the element so quickly from internal forces. The elements must be stable.

Extra high gravity may alter the filling sequence earlier too, for elements like Mercury even. I would suppose that the periodic table would be empty below Francium and Radium. And a series of elements like the Lanthanoids and Actinoids would be found from something like ununtrium {which is gaseous in our gravity constraints}.

I don't know for certain though.
Andy