Pauli's exclusion principle states that no two subshells of same element have same 4 quantum numbers.
Take example of Berrilim orbital
Electronic configuration is given by 1s²2s²
But the orbital is
[tex]\\ \rm\Rrightarrow \huge{\boxed{\uparrow\downarrow}}\:\:\huge{\boxed{\uparrow\downarrow\mid\:\:\:\:\mid\:\:\:}}[/tex]
