# Introduction for Module 12 – Electron Configurations and Quantum Numbers

Textbook: Open Stax Chemistry 2e

Suggested Reading: Chapter 6.3-6.5

Learning Objectives:

- Understand the general idea of the quantum mechanical description of electrons in an atom, and that it uses the notion of three-dimensional wave functions, or orbitals, that define the distribution of probability to find an electron in a particular part of space
- List and describe traits of the four quantum numbers that form the basis for completely specifying the state of an electron in an atom
- Derive the predicted ground-state electron configurations of atoms

- Describe and explain the observed trends in atomic size, ionization energy, and electron affinity of the elements

Captions and Attributions:

- Different orbitals have different shapes as we continue to add electrons. Figure 6.21, Shapes of s, p, d, and f orbitals by Open Stax is licensed under CC BY 4.0.
- The orbital we will fill is the lowest energy orbital, which is determined based on organization of the periodic table. Figure 6.27 This partial periodic table shows electron configurations by Open Stax is licensed under CC BY 4.0.
- The periodic table is a highly useful tool in chemistry, and demonstrates orbital filling patterns along with many other important qualities. Figure A1. The Periodic Table by Open Stax is licensed under CC BY 4.0.
- Successive Ionization energies always increase, and a large increase often relates to a core electron being removed. Table 6.3, Successive Ionization Energies for Selected Elements (kJ/mol) by Open Stax is licensed under CC BY 4.0.