A lot. Just because an electron (or more) isn't out there does not mean the shell does not exist. A shell is, if you recall, an energy level. A given atom has a given number of occupied shells in its neutral, un-ionized state. When an electron in any atom is given energy (the right amount), it can skip up to another energy level. The atom has become ionized; the electron had gone to a higher energy level. The electron then releases the energy and falls back. This ionization and de-ionization process happens continuously in gas discharge lighting (think fluorescent lights). And more applied voltage will kick electrons up to even higher energy levels. It gets more complicated. When a bunch of atoms of something are around, they have the individual "possible energy levels" as mentioned. (They're actually called Fermi energy levels.) But when some atoms are clustered together, other energy levels can exist where electronis may go that did not exist in the individual atoms. In compounds, its even more complicated. Yes, there will be a "practical upper limit" to the number of energy levels possible because at some high energy, the electronis are all torn away and the naked nucleus is left exposed. This is what happens in heavy ion colliders when atoms are stripped of their electrons and the nucleus is put into the bore of the accelerator. But those energy levels did and do exist, whether electrons are in them or not.
Shells: 3 Orbitals: 9
Magnesium has 3 electron shells. The electron configuration is : 2,8,1
As silicon is in the third row of the periodic table, it has 3 shells. (2-8-4)
the sodium atom has 3 shells where 2 electrons are in the first shell, 8 in the second and 1 in the third shell; which isn't stable..... and its symbol is Na :)
By rings, I assume you mean sub-atomic shells. Chlorine has an atomic number of 17. This means that it will have 17 electrons. The electron configuration will be as such: 2, 8, 7. Hence, chlorine will have 3 sub-atomic shells to fulfil its electronic configuration.
The uranium atom has seven electron shells.
I assume you mean energy levels/shells. It has 1.
Uranium atom has seven electron shells.
The largest atom is calcium which has 4 shells.
Selenium has four electron shells.
Shells: 3 Orbitals: 9
31 electrons, 4 rings/shells.
atoms try to get 10 electrons on shells around the atom. how many shells the atom has is based on the atomic number and atomic mass the atomic number determines how many shells their are.
Sulfur has three shells.
Einsteinium has 7 electron shells.
Lawrencium has 7 electron shells.
Promethium has 6 electron shells.