Chemical Bonding: The Covalent Bond Model

Flashcards covering the fundamentals of covalent bonding, including Lewis structures, VSEPR theory, electronegativity, bond polarity, and naming conventions for binary molecular compounds.

Covalent Bond

A chemical bond resulting from the attraction of the nuclei of two atoms to the same electrons, which results in the sharing of one or more electron pairs between those atoms.

Molecular Orbital

An orbital shared between two atoms in a molecule where the electrons are located between the two nuclei.

Octet Rule in Covalent Bonding

The principle that atoms will share electrons until each atom has a full valence shell, typically eight valence electrons, though hydrogen requires only two.

Bonding Electrons

Pairs of valence electrons that are shared between atoms in a covalent bond, often represented as dashes in Lewis structures.

Nonbonding Electrons

Pairs of valence electrons on an atom that are not involved in electron sharing, also known as lone pairs and drawn as dots.

Single Covalent Bond

A covalent bond in which two atoms share $1$ pair of electrons, represented by two dots or one dash.

Double Covalent Bond

A covalent bond in which two atoms share $2$ pairs of electrons, represented by four dots or two dashes.

Triple Covalent Bond

A covalent bond in which two atoms share $3$ pairs of electrons, represented by six dots or three dashes.

Multiple Covalent Bond

A term that refers to both double and triple covalent bonds.

Bond Strength Trend

The property that increases as the number of shared electrons increases; the order is triple bond > double bond > single bond.

Bond Reactivity Trend

The property where stronger bonds are less reactive; the order of stability is triple bond < double bond < single bond.

Coordinate Covalent Bond

A covalent bond in which both electrons in a shared pair come from only one of the two atoms in the bond.

Molecular Geometry

A description of the three-dimensional arrangement of atoms within a molecule.

VSEPR Theory

Valence-Shell Electron-Pair Repulsion Theory; a set of procedures for predicting molecular geometry based on the idea that atoms arrange themselves to minimize electron cloud repulsions.

VSEPR Electron Group

A collection of valence electrons in a localized region about the central atom, which can be a single, double, or triple bond, or a nonbonding lone pair.

Electronic Geometry

The three-dimensional arrangement of VSEPR electron groups about a central atom in a molecule.

Tetrahedral Geometry

The electronic geometry formed when there are four VSEPR electron groups around a central atom.

Electronegativity

A measure of the relative attraction that an atom has for the shared electrons in a bond, rated on a scale of $0$ to $4$. Or, specifically, Fluorine has the highest value of $4.0$.

Bond Polarity

A measure of the degree of inequality in the sharing of electrons between two atoms in a chemical bond.

Nonpolar Covalent Bond

A covalent bond in which there is equal sharing of electrons between two atoms, typically occurring when the difference in electronegativity ($\Delta EN$) is $0.4$ or less.

Polar Covalent Bond

A covalent bond in which there is unequal sharing of electrons, generally occurring when $\Delta EN$ is between $0.4$ and $1.5$, or up to $2.0$ for nonmetals.

Molecular Polarity

A measure of the degree of inequality in the attraction of bonding electrons to various locations within a molecule as a whole, dependent on both geometry and individual bond polarities.

Binary Molecular Compound

A molecular compound in which only two nonmetallic elements are present.

Systematic Prefix: Hepta-

The numerical prefix used in naming binary molecular compounds to indicate the presence of $7$ atoms.