What is the smallest possible value of the principal quantum number n for an s electron?

• A. 2
• B. 1
• C. 3
• D. 0

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 and it can only take positive integer values: \(n = 1, 2, 3, \ldots\).
2. Understand that the azimuthal (angular momentum) quantum number \(l\) determines the subshell or shape of the orbital, where \(l\) can take integer values from \$0\( to \)n-1\( for each principal quantum number \)n$.
3. Recognize that an \(s\) electron corresponds to the subshell with \(l = 0\).
4. Since \(l\) must be less than \(n\), and \(l = 0\) for an \(s\) electron, the smallest possible \(n\) that allows \(l = 0\) is \(n = 1\).
5. Therefore, the smallest principal quantum number \(n\) for an \(s\) electron is \$1$.