Question

For an atom having principal quantum number $n=4$, the electrons can occupy:

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

Answer 1

The correct option is A $s,p,d$ and $f$ orbitals.

When the principal quantum number of an atom is 1, it will contain electrons in s orbitals.
When the principal quantum number of an atom is 2, it will contain electrons in s and p orbitals.
When the principal quantum number of an atom is 3, it will contain electrons in s, p, and d orbitals.
When the principal quantum number of an atom is 4, it will contain electrons in s, p, d and f orbitals.

Hence, the correct option is A.