Question

If the principal quantum number of a shell is 2, what types of orbitals will be present?

• A. $s$
  
• B. $s$ and $p$
  
• C. $s,p$ and $d$
  
• D. $s,p,d$ and $f$
  

Answer 1

Answer: (B)

$s$ and $p$

For a shell with the principal quantum number "$n$", the types of orbitals are determined by the value of the magnetic quantum number "$l$".
For a shell with the principal quantum number "$n$", the '$l$' values ranges from $0$ to $n-1$.
When $n=2$ then '$l$' has values $=0,1$.
$l=0$ means type of the orbitals is s-orbital.
$l=1$ means type of orbitals is p-orbital.
Hence, there are $s$ and $p$ orbitals for a shell with the principal quantum number "$n$".