How many sub-shells present in a 'M' principal energy shell?

How many sub-shells are present in a principal energy shell ?

How many sub-shells are present in M-shell ?

How many shells are present in lanthanide

The sub shells present in L shell are

How many types of sub-shells are present in the fourth energy level of an atom? Write the total number of orbitals.

How many sub-shells are associated with n = 4 ?

How many sub-shells are associated with n = 5 ?

How many sub-shells ssociated with n=4?