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!
An orbital can only occupy maximum of 2 electrons. As p orbital consist of 3 orbitals. And has 3 orientations. Px, Py, Pz. So as there are 3 orbitals so p orbital can occupy at the maximum 6 electrons regardless of principle quantum no.. In 4p 4 is principle quantum no. So it represent 4p represent the p orbital of 4th shell. So it also occupy at the maximum of 6 electrons.
No, there are only 4g orbitals in an atom - s, p, d, and f. Electrons can occupy these orbitals based on their energy levels and quantum numbers.
There can only be 2 electrons in each single orbital, and they will be on opposite sides of the electron cloud (orbital).
All other orbitals at the sub contain at least one electron
The first orbital of hydrogen, which is the 1s orbital, can hold a maximum of 2 electrons.
Spin
they have opposite spin
No. Electrons are fermions, meaning they cannot share the same set of four quantum numbers. Usually when we say "orbital" we only mean the first three, so there is room for two electrons in an orbital (corresponding to the two possible ms values).
only if spins are opposite: one up one down.
An orbital can only occupy maximum of 2 electrons. As p orbital consist of 3 orbitals. And has 3 orientations. Px, Py, Pz. So as there are 3 orbitals so p orbital can occupy at the maximum 6 electrons regardless of principle quantum no.. In 4p 4 is principle quantum no. So it represent 4p represent the p orbital of 4th shell. So it also occupy at the maximum of 6 electrons.
In any shell excluding shell1, there is only 1 s orbital and 1 p orbital. Subshells and the Orbitals are same. Orbital g is known as subshell 5. g orbital is present shell 6. But till today no element is discovered with an electron in g orbital.
The maximum number of electrons that can occupy the 5s orbital is 2. This is based on the Pauli exclusion principle, which states that each orbital can hold a maximum of two electrons with opposite spins.
No, there are only 4g orbitals in an atom - s, p, d, and f. Electrons can occupy these orbitals based on their energy levels and quantum numbers.
There can only be 2 electrons in each single orbital, and they will be on opposite sides of the electron cloud (orbital).
There are ONLY 2 valence electrons in Co, valence electrons come only from the s orbital and the p orbital, giving only 2 for Cobalt.
All other orbitals at the sub contain at least one electron
The first orbital of hydrogen, which is the 1s orbital, can hold a maximum of 2 electrons.