Maximum number of electrons in a subshell with l = 3 and n = 4 is:
14
First take a look at values of n and l.
n = 4
l = 3
Therefore possible orientions = 2l + 1= 2(3) + 1 = 7
Number of orbitals = 7
∴ Maximum number of electrons in one orbital = 2
⇒ Maximum number of electrons =7×2=14