A Level Chemistry OCR Practice Exam

What does the term "electron configuration" refer to in chemistry?

1. The structure of ionic compounds

2. The arrangement of atoms in a molecule

3. The arrangement of electrons in an atom

4. The energy levels of electrons

The correct answer is: The arrangement of electrons in an atom

The term "electron configuration" specifically refers to the arrangement of electrons in an atom. It describes how electrons are distributed among the various atomic orbitals and energy levels. This configuration is crucial for understanding the chemical properties of an element, as it determines how an atom can bond with other atoms. The electron configuration is usually written using a series of numbers and letters indicating the energy levels and types of orbitals occupied by electrons, such as 1s² 2s² 2p⁶ for neon. Other options refer to aspects of chemistry that, while important, do not define "electron configuration." The structure of ionic compounds relates to how ions are arranged in a lattice rather than electron distribution in individual atoms. Similarly, the arrangement of atoms in a molecule focuses on interatomic bonds instead of electron locations, and while energy levels are related to electron configuration, they do not encompass the full details of how electrons occupy those levels. Thus, the most accurate definition of "electron configuration" is the arrangement of electrons in an atom.