Who hypothesized that only two electrons can occupy an orbital?

Answer 1

The bottom-line answer is because that is how nature works! However, there are somewhat less profound explanations, but they are really just rules which say that this must happen -- and don't ultimately answer "Why?".

The Pauli Exclusion Principle says that all electrons in an atom must have four unique quantum numbers -- no two can have all four the same. This rule forbids more than 2 electrons existing in the same orbital because there are two possible quantum numbers available for that orbital -- electron spin of +1/2 and -1/2.

But again, this rule just says that there can't be more than 2 electrons per orbital because of the uniqueness of quantum numbers -- but it doesn't say why quantum numbers must be unique! In the end, it really just is the way it because that's the way it is!

Answer 2

No two electrons in an orbital can have the same spin number; if one is +1/2, the other MUST be -1/2. This fact is in keeping with a fundamental principle of quantum physics called the Pauli exclusion principle, which states that no two electrons in an atom may have the same set of four quantum numbers.

Answer 3

Electrons are negatively charged and repel each other. The presence of a maximum of 2 electrons in one orbital is itself surprising. The reason for this is that the two electrons have opposite spins which enables this.

Answer 4

Two Electrons occupy the same orbital when they are no over lower energy orbital.

E.g:

1s1 Has 1 electron in it's orbital.

1s2 Has 2 electrons in its orbital as 2s has more energy therefore the electrons go to the 1s to fill in first.

Orbitals can contain only 2 electrons at a time which so in DIFFRENT directions

S orbitals have a maximum of 2 electrons

P orbitals have a maximum of 6 electrons

D orbials have a maxium of 10 electrons

F orbitals have a maximum of 14 electrons

G orbitals have a maximum of 18 electrons

Answer 5

The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925.

In its simplest form for electrons in a single atom, it states that no two electrons can have the same four quantum numbers.

So in the same orbital, defined by one 'tri' set of quantum numbers (n, l, and ml ) the spin quantum number differs; the two values, being ms = +1/2 and ms = -1/2, are each taken by one electron.

Answer 6

Both electrons should have a different spin quantumnumber, for which there are only two possibilities:

CW = +1/2 and CCW = -1/2.

Each electron has its own set of quantum numbers.

Answer 7

There are only two spins possible, so if there were more than two electrons in an orbital, two of the three electrons would have the same spin and they would fly apart.

A more advanced explanation is that this is a principle of quantum mechanics, Paulis exclusion principle, which applies to fermions. Spin is quantised, and is +(1/2) or -(1/2). Two electrons in the same orbital cannot have the same spin quantum number.

Answer 8

The basic rule (the Pauli exclusion principle) is that two particles (of a certain type, called "fermions") can't have the same quantum state. Two electrons may be in the same orbital, but opposite spins. In that case, the other quantum numbers are the same, but the combination of all four quantum numbers doesn't match, so there is no problem with the Pauli exclusion principle.