Lewis Dot Structures

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Lewis Dot Structure Noun

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[loo-is dot struk-cher]

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Lewis Dot Structure

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A diagram showing the bonding between atoms in a molecule and the lone pairs of electrons that may exist.

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Example: This diagram shows a water molecule (H₂O), where lines represent shared electrons (bonds) and dots represent unshared valence electrons, illustrating a Lewis Dot Structure.

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Valence Electrons Noun

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[vay-lence i-lek-trons]

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Valence Electrons

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The electrons in the outermost shell of an atom that are available to participate in forming chemical bonds with other atoms.

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Example: This diagram of a sodium atom shows electrons in shells; the single electron in the outermost shell is its one valence electron.

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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 such a way that they each have eight electrons in their valence shell.

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Example: Atoms like Fluorine, with seven outer electrons, share electrons with other atoms to form a stable molecule where each atom has a full outer shell of eight electrons.

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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 are not shared with another atom in a covalent bond and belong to one atom.

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Example: This Lewis dot structure of an ammonia molecule shows a lone pair as two valence electrons on the nitrogen atom that are not shared in a bond.

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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 are shared between two atoms, creating a covalent bond that holds the atoms together.

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Example: This diagram shows a bonding pair as the two blue dots (electrons) shared between the nitrogen (N) and hydrogen (H) atoms, forming a bond.

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Ionic Bond Noun

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[eye-on-ik bond]

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Ionic Bond

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A chemical bond formed by the transfer of electrons from a metal to a non-metal, creating oppositely charged ions.

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Example: This diagram shows a sodium (Na) atom giving one electron to a chlorine (Cl) atom, forming an ionic bond between the resulting positive and negative ions.

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Covalent Bond Noun

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[koh-vay-lent bond]

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Covalent Bond

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A chemical bond that involves the sharing of one or more electron pairs between atoms to form a stable molecule.

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Example: This diagram shows a water molecule where one oxygen atom shares electrons with two hydrogen atoms, forming two distinct covalent bonds.

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Cation Noun

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[kat-eye-on]

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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: This image shows a neutral sodium atom (Na) losing its single outer electron to become a positively charged sodium ion (Na+), which is a cation.

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Anion Noun

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[an-eye-on]

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Anion

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

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Example: A neutral chlorine atom gains an electron to fill its outer shell, becoming a negatively charged chloride anion (Cl⁻).

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Central Atom Noun

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[sen-trul at-um]

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Central Atom

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The atom in a polyatomic molecule that is bonded to two or more other atoms, typically the least electronegative one.

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Example: This image shows the basic parts of a single atom, like protons and electrons, but it does not show a 'central atom' which is an atom bonded to other atoms in a molecule.