How many sublevels are present in the principal energy level where n = 3?

• A. 1
• B. 3
• C. 4
• D. 2

Answer: (B)

Verified step by step guidance

1. Recall that the principal quantum number \( n \) defines the main energy level or shell of an electron in an atom.
2. Understand that for each principal energy level \( n \), the number of sublevels (or subshells) is equal to \( n \).
3. Each sublevel corresponds to a different value of the azimuthal quantum number \( l \), which ranges from 0 to \( n-1 \).
4. For \( n = 3 \), the possible values of \( l \) are 0, 1, and 2, which correspond to the \( s \), \( p \), and \( d \) sublevels respectively.
5. Therefore, the number of sublevels in the principal energy level \( n = 3 \) is 3.