Electron Configuration

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Electron Configuration Noun

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[uh-lek-tron kon-fig-yuh-rey-shuhn]

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Electron Configuration

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The specific arrangement and distribution of electrons in the atomic orbitals of an atom or molecule.

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Example: This Bohr model diagram shows how electrons are arranged in shells around an atom's nucleus, with the numbers 2, 8, 1 representing the electron configuration.

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Ground-State Electron Configuration Noun

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[ground-steyt uh-lek-tron kon-fig-yuh-rey-shuhn]

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Ground-State Electron Configuration

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The most stable, lowest-energy arrangement of electrons in the orbitals of an atom.

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Example: This diagram shows electrons filling the shells closest to the nucleus first, representing the atom's most stable, or 'ground-state,' electron configuration.

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Aufbau Principle Noun

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[ouf-bou prin-suh-puhl]

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Aufbau Principle

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The rule stating that electrons fill atomic orbitals from the lowest available energy levels before occupying higher levels.

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Example: This diagram shows the order that electrons fill energy levels (orbitals) in an atom, starting from the lowest energy (1s) and following the path.

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Pauli Exclusion Principle Noun

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[paw-lee ik-skloo-zhuhn prin-suh-puhl]

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Pauli Exclusion Principle

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The principle that a maximum of two electrons can occupy a single atomic orbital, but only if they have opposite spins.

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Example: This diagram shows that for two electrons to share an orbital (the box), they must have opposite spins (one arrow up, one down), which is 'Allowed'.

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Hund's Rule Noun

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[hundz rool]

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Hund's Rule

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The rule that electrons will occupy separate orbitals within a sublevel before pairing up in the same orbital.

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Example: This diagram shows that electrons fill empty orbitals in a subshell first before pairing up, which is the core principle of Hund's Rule.

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Atomic Orbital Noun

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[uh-tom-ik awr-bi-tl]

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Atomic Orbital

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A three-dimensional region around an atom's nucleus that describes the probable location of up to two electrons.

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Example: This image shows the shapes of atomic orbitals, which are regions around an atom's nucleus where an electron is most likely to be found.

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Energy Sublevel Noun

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[en-er-jee suhb-lev-uhl]

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Energy Sublevel

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A set of orbitals within a principal energy level that have the same energy, designated s, p, d, or f.

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Example: This diagram shows that an atom's main energy levels (labeled 1, 2, 3, 4) are divided into smaller energy sublevels (labeled s, p, d, f).

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Principal Energy Level Noun

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[prin-suh-puhl en-er-jee lev-uhl]

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Principal Energy Level

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The main energy level of an atom, denoted by the principal quantum number 'n', indicating the orbital's size.

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Example: This diagram shows a central nucleus surrounded by distinct paths, or shells, labeled E₁, E₂, etc., which represent the different principal energy levels.

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Electron Spin Noun

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[uh-lek-tron spin]

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Electron Spin

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An intrinsic quantum property of an electron that gives it angular momentum, with two possible directions (spin up or down).

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Example: An electron's spin creates a tiny magnetic field, acting like a mini-magnet with a north and south pole, pointing in one of two opposite directions.

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Orbital Diagram Noun

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[awr-bi-tl dahy-uh-gram]

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Orbital Diagram

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A visual representation of electron configuration where orbitals are shown as boxes and electrons are represented by arrows.

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Example: This diagram shows how electrons (arrows) fill different energy levels and orbitals (lines), starting from the lowest energy level (1s) and moving up.