Skip to main content
Ch.6 - Electronic Structure of Atoms
Chapter 6, Problem 56

How many unique combinations of the quantum numbers l and ml are there when (a) n = 1 (b) n = 5?

Verified step by step guidance
1
insert step 1> Determine the possible values of the azimuthal quantum number \( l \) for a given principal quantum number \( n = 5 \). The values of \( l \) range from 0 to \( n-1 \).
insert step 2> List the possible values of \( l \) for \( n = 5 \): \( l = 0, 1, 2, 3, 4 \).
insert step 3> For each value of \( l \), determine the possible values of the magnetic quantum number \( m_l \). The values of \( m_l \) range from \( -l \) to \( +l \).
insert step 4> Calculate the number of \( m_l \) values for each \( l \): \( l = 0 \) has 1 value, \( l = 1 \) has 3 values, \( l = 2 \) has 5 values, \( l = 3 \) has 7 values, and \( l = 4 \) has 9 values.
insert step 5> Add the number of \( m_l \) values for all \( l \) to find the total number of unique combinations of \( l \) and \( m_l \) for \( n = 5 \).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Quantum Numbers

Quantum numbers are sets of numerical values that describe the unique quantum state of an electron in an atom. There are four quantum numbers: principal (n), azimuthal (l), magnetic (ml), and spin (ms). Each quantum number provides specific information about the electron's energy level, shape of the orbital, orientation, and spin direction.
Recommended video:
Guided course
02:55
Principal Quantum Number

Principal Quantum Number (n)

The principal quantum number (n) indicates the main energy level or shell of an electron in an atom. It can take positive integer values (1, 2, 3, ...), with higher values corresponding to higher energy levels and greater distances from the nucleus. In this case, n = 5 means we are considering the fifth energy level.
Recommended video:
Guided course
02:55
Principal Quantum Number

Azimuthal Quantum Number (l) and Magnetic Quantum Number (ml)

The azimuthal quantum number (l) defines the shape of the orbital and can take values from 0 to n-1. For n = 5, l can be 0, 1, 2, 3, or 4, corresponding to s, p, d, f, and g orbitals, respectively. The magnetic quantum number (ml) specifies the orientation of the orbital and can take values from -l to +l, resulting in multiple ml values for each l, thus creating unique combinations.
Recommended video:
Guided course
03:06
Magnetic Quantum Number