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.
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
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.
2. Two electrons of opposite spin. This is true of all s, p, d, f g.... orbitals, eah can only contain two electrons of opposite spin.
Electrons have spin of a 1/2. These make electrons fermions. According to Pauli's exclusion principle, no more than one fermion can have the same spin in the same space. So, the electrons occupying the same space must have opposite spin (and so, only two electrons can occupy the same orbital as a result of this, as three electrons will results in two electrons having the same spin state).
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.
s-orbital = 2e- (s) orbital can hold 2 electrons, each with opposite spin. p-orbital = 6e- (p) orbital can hold 6 electrons in 3 suborbitals, so 2 electrons in each d-orbital = 10e- (d) orbital can hold 10 electrons in 5 suborbitals, so 2 electrons in each f-orbital = 14e- (f) orbital can hold 14 electrons in 7 suborbitals, so 2 electrons in each
there are two electons in the s sublevel. It is the number of electrons that fit in the first orbital around an atom.
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.