Electron Configuration

Front

Electron Configuration Noun

---

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

Back

Electron Configuration

---

The specific arrangement and distribution of electrons within an atom's orbitals and energy levels, dictating its chemical properties.

---

Example: This diagram shows how electrons are arranged in specific energy levels, or shells, orbiting the nucleus of an atom, which defines its electron configuration.

Front

Quantum Mechanical Model Noun

---

[kwon-tuhm muh-kan-i-kuhl mod-l]

Back

Quantum Mechanical Model

---

An atomic model that treats electrons as waves, describing their location in terms of probabilities within three-dimensional orbitals.

---

Example: This model shows a central nucleus with protons and neutrons, surrounded by a 'cloud' representing the probable locations of electrons, not fixed orbits.

Front

Atomic Orbital Noun

---

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

Back

Atomic Orbital

---

A three-dimensional region around an atom's nucleus where there is a high probability of finding a specific electron.

---

Example: This image shows the different shapes of atomic orbitals (s, p, d, f), which are regions around an atom's nucleus where electrons are likely to be found.

Front

Electron Energy Level Noun

---

[uh-lek-tron en-er-jee lev-uhl]

Back

Electron Energy Level

---

A fixed distance from an atom's nucleus where electrons with a specific amount of energy may be found, also known as a shell.

---

Example: This Bohr model shows electrons arranged in specific energy levels or shells around a Sodium nucleus, with 2 in the first level, 8 in the second, and 1 in the third.

Front

Sublevel Noun

---

[suhb-lev-uhl]

Back

Sublevel

---

A division within an electron energy level, designated by letters (s, p, d, f) corresponding to specific orbital shapes.

---

Example: This image shows the different shapes of electron sublevels: the spherical 's' sublevel, the dumbbell-shaped 'p' sublevel, and the clover-shaped 'd' sublevel.

Front

Aufbau Principle Noun

---

[ouf-bou prin-suh-puhl]

Back

Aufbau Principle

---

The rule stating that electrons must occupy the lowest energy orbitals available before filling any higher energy orbitals.

---

Example: This diagram shows the order for filling electron orbitals, starting from the lowest energy level (1s). Following the arrows gives the correct sequence for building an atom's electron configuration.

Front

Pauli Exclusion Principle Noun

---

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

Back

Pauli Exclusion Principle

---

The rule stating that a single atomic orbital can hold a maximum of two electrons, which must have opposite spins.

---

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

Front

Hund's Rule Noun

---

[hundz rool]

Back

Hund's Rule

---

The rule stating that electrons will singly occupy each orbital in a sublevel before any orbital is doubly occupied.

---

Example: This diagram shows how electrons fill empty spaces (orbitals) one at a time before they start pairing up, which creates a more stable atom.

Front

Valence Electrons Noun

---

[vey-luhns uh-lek-trons]

Back

Valence Electrons

---

The electrons located in the outermost energy level of an atom, which are primarily involved in chemical bonding.

---

Example: This Bohr model of an oxygen atom shows six electrons in the outermost shell, which are the valence electrons that determine its chemical properties.

Front

Electron-Dot Structure Noun

---

[uh-lek-tron dot struhk-cher]

Back

Electron-Dot Structure

---

A diagram using dots to represent the valence electrons of an atom, placed around the element's chemical symbol.

---

Example: This diagram shows how two hydrogen atoms share their single valence electrons to form a covalent bond, which is represented by the electron-dot structure H:H.