What are atomic energy levels?

[RohitRmB]

what are atomic energy levels? are they different in principle to electron energy levels?
how to visualize atomic energy levels in any substance (solid, liquid and gas)
I have read that during the formation of bose einstein condensate all the atoms comes to ground level from high energy levels but I am not able to visualize it or think of it.
what will happen if we freeze a solid substance to near a millionth above absolute zero, does the substance loose its shape?

 

[sophiecentaur]

Welcome.
The energy levels 'of an electron' are really related to the electron's behaviour in the presence of the nucleus (and the other electrons) so it is more precise to refer to the energy of the whole system of charges (the atom) than just the electron. But both terms tend to be used.

 

[voko]

For a hydrogen atom, both terms mean exactly the same thing. Other atoms have more than one electron, so the energy levels of the entire system will necessarily be different from that of any electron comprising the atom. However, the terms are often used interchangeably.

 

[RohitRmB]

but how can a atom have a energy level?
how to visualize it?

 

[RohitRmB]

can anyone suggest a book explaining in great detail the energy levels of electrons or energy level of atoms?
a school level books addressed to students who have just started to learn these topics

 

[Vanadium 50]

Of course not. "In great detail" and "just started to learn these topics" are mutually exclusive.

 

[sophiecentaur]

but how can a atom have a energy level?
how to visualize it?

If you call the energy level the 'electron energy level' then you are making huge assumptions.
If you had a spring which could be stretched over a ratchet, then you could say that the energy stored would be in 'discrete energy levels'. This wouldn't refer to the level of just one end of the spring, but the whole thing. In the same way, the proton and the electron, in the simplest case of an H atom, are both involved with the energy that the atom can absorb or emit. Hence, you can argue that the energy level refers to the whole atom.

If you take a massive rock and lift it, the Earth will move a small distance the other way. Although we would normally say that the energy is all stored in the rock, by virtue of its height, the energy is as much due to the Earth as to the rock. In this case, the ratio of the masses is millions and millions to one, whereas the ratio of masses for the H atom is only 1800:1. In atoms of higher atomic number, the energy levels definitely relate to all the electrons (plus nucleus) rather than just to one electron. Hence - 'atomic' energy level is a more accurate description.

 

[Naty1]

You can find some very good illustrations of electron energy levels [orbitals] here:
Be sure to scan all the way down the page..lots of illustrations.


http://en.wikipedia.org/wiki/Atomic_orbital

There are dozens of explanatory links withn the article.

Be sure to read this section:

Modern conceptions and connections to the Heisenberg Uncertainty Principle

After you have an idea of the above, also check out 'molecular orbitals': You'll find some changes occur there. Wikipedia has a few illustrations.

It turns out electrons assume some different characteristics, like size and orbtial energies,for example, when in molecular assemblies rather than an isolated atom. If you are familiar with waves, you can think of these changes as differences in constructive and destructive interference for a start.

Analogous to string theory {where the number and size of extra dimensions affect particle characteristics} when in atoms and molecules the physical surroundings also affect particle characteristics.