Skip to main content
Ch.5 - Periodicity & Electronic Structure of Atoms
Chapter 5, Problem 82

What is the maximum number of electrons in an atom whose highest-energy electrons have the principal quantum number n = 5?

Verified Solution

Video duration:
6m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

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

Principal Quantum Number (n)

The principal quantum number, denoted as 'n', indicates the energy level of an electron in an atom. It can take positive integer values (1, 2, 3, ...), with higher values corresponding to electrons that are further from the nucleus and have higher energy. For n = 5, the electrons are in the fifth energy level.
Recommended video:
Guided course
02:55
Principal Quantum Number

Electron Capacity of Energy Levels

Each principal energy level can hold a maximum number of electrons determined by the formula 2n², where 'n' is the principal quantum number. For n = 5, the maximum number of electrons is calculated as 2(5)² = 50. This capacity reflects the arrangement of electrons in various sublevels and orbitals within that energy level.
Recommended video:
Guided course
02:19
Heat Capacity

Sublevels and Orbitals

Energy levels are divided into sublevels (s, p, d, f), which contain orbitals where electrons reside. Each sublevel has a specific number of orbitals: s has 1, p has 3, d has 5, and f has 7. The distribution of electrons among these sublevels influences the chemical properties of the atom, but the total number of electrons is still limited by the maximum capacity of the principal energy level.
Recommended video:
Guided course
03:06
Molecular Orbital Theory