Chemical Bonding

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Octet Rule Noun

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[ok-tet rool]

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Octet Rule

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The principle that atoms tend to bond in a way that gives them eight electrons in their valence shell.

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Example: This atom has eight electrons in its outer shell, which is a full and stable arrangement that other atoms try to achieve.

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Covalent Bond Noun

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[koh-vey-luhnt bond]

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Covalent Bond

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A chemical bond formed when two atoms achieve stability by sharing one or more pairs of their valence electrons.

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Example: This diagram shows two hydrogen atoms and one oxygen atom forming covalent bonds by sharing their outer electrons to become a stable water molecule.

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Bonding Pair Noun

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[bon-ding pair]

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Bonding Pair

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A pair of electrons that is shared between two atoms in a chemical bond, holding the atoms together.

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Example: This model shows atoms connected by sticks, where each stick represents a bonding pair—the two shared electrons that hold the atoms together.

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Lone Pair Noun

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[lohn pair]

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Lone Pair

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A pair of valence electrons that is not involved in bonding and belongs exclusively to one atom in a molecule.

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Example: This image shows a water molecule (H₂O). The two yellow lobes on the central oxygen atom represent the lone pairs of electrons, which are not involved in bonding.

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Ionic Bond Noun

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[ahy-on-ik bond]

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Ionic Bond

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The electrostatic force of attraction that holds oppositely charged ions together in an ionic compound after electron transfer.

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Example: This image shows how positive sodium ions (Na+) and negative chloride ions (Cl-) attract each other to form a strong, repeating crystal structure.

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Ionic Compound Noun

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[ahy-on-ik kom-pound]

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Ionic Compound

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An electrically neutral compound composed of positively charged cations and negatively charged anions held together by ionic bonds.

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Example: A sodium atom transfers an electron to a chlorine atom, forming a positive sodium ion and a negative chloride ion, which then attract.

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Cation Noun

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[kat-ahy-uhn]

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Cation

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A positively charged ion that is formed when a neutral atom loses one or more of its valence electrons.

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Example: A neutral sodium atom loses one electron from its outer shell, becoming a positively charged sodium ion (Na+), which is a cation.

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Anion Noun

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[an-ahy-uhn]

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Anion

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A negatively charged ion that is formed when a neutral atom gains one or more valence electrons.

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Example: An atom becomes a negatively charged anion when it gains one or more electrons, as shown by the electron moving to the atom.

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Crystal Lattice Noun

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[kris-tl lat-is]

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Crystal Lattice

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An orderly, repeating three-dimensional arrangement of ions, atoms, or molecules that forms the structure of a crystalline solid.

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Example: This image shows a crystal lattice as an orderly, repeating pattern of atoms, which is characteristic of crystalline solids like salt or snowflakes.

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Unit Cell Noun

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[yoo-nit sel]

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Unit Cell

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The smallest repeating structural unit of a crystal lattice that shows the three-dimensional pattern of the entire crystal.

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Example: This image shows a unit cell, the smallest repeating building block of a crystal, similar to how one brick is part of a whole wall.