Answer :
Electronic configuration of the atom describes the arrangemnet of electrons in different shells and subshells ( sublevels).
Now , there are 4 types of sublevels: s, p , d and f . These sublevels have orbital which are spaces with high probability of having an electron and each orbital can have maximum 2 electrons.
Therefore,
s-sublevel has 1 orbital - it can have maximum 2 electrons.
p-sublevel has 3 orbitals - it can have maximum 6 electrons
d-sublevel has 5 orbitals - it can have maximum 10 electrons
f-sublevel has 7 orbitals - it can have maximum 14 electrons.
Hence, the acsending order of sublevels in terms of maximum number of electrons is:
s < p < d < f
s-sublevel has 1 orbital - it can have maximum 2 electrons.
p-sublevel has 3 orbitals - it can have maximum 6 electrons
d-sublevel has 5 orbitals - it can have maximum 10 electrons
f-sublevel has 7 orbitals - it can have maximum 14 electrons.