Quantum numbers that label electron states in atoms Which set lists the standard symbols for the three quantum numbers commonly used to describe an electron's state (principal, azimuthal/orbital, and magnetic, excluding spin)?

Introduction / Context:
Atomic orbitals are labeled by quantum numbers that arise from solutions of the Schrödinger equation in a central potential. Recognizing the correct symbols is foundational for interpreting spectroscopy, selection rules, and periodic trends.

Given Data / Assumptions:

• Spin is excluded; only principal, orbital (azimuthal), and magnetic quantum numbers are considered.
• Standard spectroscopic notation is used.

Concept / Approach:
The three quantum numbers are: n (principal), l (orbital/azimuthal), and m (magnetic). They determine shell, subshell, and orientation of the orbital angular momentum with respect to a quantization axis. Spin adds a fourth quantum number m_s, but it is not part of this question.

Step-by-Step Solution:
Identify principal quantum number → n.Identify orbital (azimuthal) quantum number → l.Identify magnetic quantum number → m (sometimes written m_l).Therefore the correct set is n, m, l (ordering is not critical as long as the symbols are correct).

Verification / Alternative check:
Chemistry and physics textbooks consistently use (n, l, m_l, m_s).

Why Other Options Are Wrong:
Other symbol sets are not standard or mix in unrelated constants (e.g., h is Planck’s constant, k often denotes wave number or Boltzmann’s constant).

Common Pitfalls:

• Confusing m (magnetic) with m_s (spin).
• Using letter-based subshell labels (s, p, d, f) instead of the underlying l values.

Final Answer:
n, m, l