According to this law, if two electrons are in the same orbit, then the spin directions of these two electrons must be opposite. In other words, each orbit can only hold two electrons with opposite spin directions.
According to the Pauli exclusion principle, it is known that the S sublayer has only 1 orbit, which can accommodate two electrons with opposite spins. The p sublayer has three orbits, which can accommodate six electrons in total; The D sublayer has five orbitals, which can hold 10 electrons in total.
The first electron layer (k layer) has only 1s sublayer, which can accommodate at most two electrons; The second electron layer (L layer) includes two sublayers, 2s and 2p, which can hold 8 electrons in total. The third electron layer (M layer) includes 3s, 3p and 3d sublayers, which can hold 18 electrons in total ... The nth layer can hold 2n^2 electrons in total.
Extended data
Coulomb attraction between electrons and protons binds electrons to atoms, which is called bound electrons. More than two atoms will exchange or share their bound electrons, which is the main reason for the formation of chemical bonds.
When an electron leaves the nucleus and can move freely, it is called a free electron. The phenomenon of net flow caused by many free electrons moving together is called current. Electrons play an important role in many physical phenomena, such as electricity, magnetism or heat conduction. Moving electrons will generate a magnetic field and will also be deflected by an external magnetic field. Electrons that accelerate will emit electromagnetic radiation.
Baidu Encyclopedia-Extranuclear electron configuration's Law of Atoms
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