Electron Configurations and Quantum Numbers
Learning Objective
I can determine the electron configuration of an element using quantum numbers and the Aufbau principle.
Key Concepts
The four quantum numbers that describe different atomic orbitals are the principal quantum number (n), the angular momentum quantum number (l), the magnetic quantum number (m sub l), and the spin quantum number (m sub s).
The Aufbau principle tells us the order in which an atom will fill up its orbitals, and Hund's rule says that for electrons of the same energy, you put one electron in each orbital first before doubling them up.
Atoms with unpaired electrons in their orbital diagrams are called paramagnetic and are attracted by a magnetic field, while atoms with all of their electrons paired are diamagnetic and are not affected by a magnetic field.
Practice Questions
This lesson includes 12 practice questions to reinforce learning.
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1. What do quantum numbers describe regarding each electron in an atom?
2. Which quantum number determines the energy level of an electron?
3. What are the possible values for the spin quantum number (m sub s)?
...and 9 more questions
Educational Video
Quantum Numbers, Atomic Orbitals, and Electron Configurations
Professor Dave Explains