Question

How many electrons does s, p, d, f can hold?

Answer 1

We know that s, p, d, f are the subshells in the atoms and the electrons are filled in accordance with the Pauli exclusion principle given by Austrian physicist Wolfgang Pauli in $1925$.

Complete step by step answer:
Before heading directly to the answer you must first understand the Pauli exclusion principle. The Pauli exclusion principle states that no two fermions (for example electrons) cannot have all the quantum numbers same and thus cannot occupy the identical quantum state. Thus, each sub-orbital can only hold two electrons with the different spin quantum number.
The orbitals are the space around the nucleus where there is a higher probability to find an electron. s, p, d, f are the different subshells which are the collection of few orbitals. s subshell has only one orbital, p subshell has three orbitals, d subshell has five orbitals and f subshell has seven orbitals. Now, according to Pauli exclusion principle, each orbital must have only two electrons, thus, s subshell has two electrons, p subshell has six electrons, d subshell has ten electrons and f subshell has fourteen electrons in total.
There is also a trick to remember the number of electrons in each subshell given below:
The number of orbitals in s, p, d, f are $1,{{ }}3,{{ }}5,{{ }}7$ which are the first positive odd integers on the number line. Now, we multiply each integer by $2$ to get the number of electrons. In this way, s subshell has two electrons, p subshell has six electrons, d subshell has ten electrons and f subshell has fourteen electrons in total.

Note: The s, p, d, f subshells are further arranged into shells with different and distinct energy levels. These shells contain $2{n^2}$ electrons, meaning the first shell contains two electrons (which is where $1s$ comes from), the second $8$, the third $18$, and so on.