The outer electrons of the nucleus are excreted

When an atom is in a base state, the outer electrons of the nucleus are scheduled according to three principles:
(
1)The principle of bubble incompatibility
- an atomic orbit can hold up to two electrons and spin in the opposite direction. Or, in the same atom, there are no electron layers, electron sub-layers, electron clouds extending in exactly the same direction as electron spin states. Each electron layer can hold up to 2n
2
electrons,
n is the electronic layer label. (
2)minimum energy principle
- Under the premise of meeting the bubble principle, electrons will be filled according to the principle of making the total energy of the system the lowest. Quantum chemical calculations show that when there is d electron filling (e.g. fourth cycle Ni, 3d orbital energy E
3d
-18.7eV, E 4s
-7.53eV), E 3d
<
E
4s
; when there are no
d electrons (e.g., cycle K, E
3d
-0.64eV, while E 4s
-4.00eV) E 3d
>
E
4s
, energy-level
"inverted" phenomenon, other fifth, sixth and seventh cycles have a similar situation. Therefore, it cannot simply be said that electrons can be filled in the order in which the orbit can be filled from low to high, but it can always be said to be filled in the order from small to large with n-0.7l values. where n is the main quantum number and l is the adverb quantum number. (3) Hunt Rule - In orbits with equal energy in each sub-layer, electrons occupy as many orbits as possible and have the same spin state.