📚 Topic Summary
Electron configuration describes how electrons are arranged within an atom. These arrangements determine the chemical properties of an element. Electrons fill energy levels and sublevels in a specific order, following the Aufbau principle, Hund's rule, and the Pauli exclusion principle. Understanding these rules is key to predicting how elements will interact to form chemical bonds. Electron configurations can be written in full form (e.g., $1s^22s^22p^6$) or in noble gas shorthand (e.g., $[Ne]3s^1$).
Accurately determining electron configurations allows scientists to predict an element’s reactivity and its position on the periodic table. This foundation unlocks understanding of more advanced concepts in chemistry.
🧪 Part A: Vocabulary
Match the term to its correct definition:
| Term |
Definition |
| 1. Aufbau Principle |
A. States that each orbital in a sublevel is singly occupied before it is doubly occupied. |
| 2. Hund's Rule |
B. No two electrons in the same atom can have the same set of four quantum numbers. |
| 3. Pauli Exclusion Principle |
C. Electrons first fill the lowest energy levels available. |
| 4. Valence Electrons |
D. The outermost electrons of an atom that participate in chemical bonding. |
| 5. Orbital |
E. The space around the nucleus where there is a high probability of finding an electron. |
💡 Part B: Fill in the Blanks
Complete the following paragraph using the words: electrons, sublevels, energy levels, orbitals, configuration.
The electron _________ of an atom describes the arrangement of _________ within its _________. These levels are further divided into _________, which consist of _________. Each orbital can hold a maximum of two electrons with opposite spins.
🧠 Part C: Critical Thinking
Explain how the electron configuration of an element relates to its position on the periodic table. Give a specific example.
