Chemistry Unit Test | Covalent Compounds

Covalent Bond

A chemical bond formed when two atoms share one or more pairs of electrons.

Octet Rule

The principle that atoms tend to bond in such a way that they each have eight electrons in their valence shell, achieving a noble gas electron configuration.

Sigma Bond

A type of covalent bond that occurs when the pair of shared electrons is in an area centered between the two atoms.

Pi Bond

A type of covalent bond formed when parallel orbitals overlap and share electrons.

Bond Length

The distance between the nuclei of two bonded atoms.

Bond Dissociation Energy

The amount of energy required to break one mole of a bond in a substance.

Diatomic Molecule

A molecule consisting of two atoms.

Resonance Structures

Two or more valid Lewis structures that can depict the same molecule.

Hybridization

The process of mixing atomic orbitals to form new hybrid orbitals.

Electronegativity

The relative ability of an atom to attract electrons in a chemical bond.

Polar Covalent Bond

A type of bond where electrons are shared unequally between two atoms, resulting in a dipole.

VSEPR Theory

A model used to predict the geometry of molecular structures based on minimizing electron pair repulsion.

Covalent Network Solid

A type of solid in which atoms are connected by a network of covalent bonds.

Hydrogen Bond

A strong type of dipole-dipole attraction between molecules, specifically involving hydrogen bound to fluorine, oxygen, or nitrogen.

Oxyacid

An acid that contains hydrogen and an oxyanion.

Suboctet

A stable configuration where an atom has fewer than eight electrons in its valence shell.

Expanded Octet

A stable configuration where an atom has more than eight electrons in its valence shell, typical of elements in period 3 or higher.

Van der Waals Forces/ London Dispersion Forces

The weak attractions between molecules resulting from temporary dipoles.

Dipole

A pair of equal and oppositely charged or magnetized poles separated by a distance.

Electron Affinity

The energy change that occurs when an atom gains an electron.

Molecular Geometry

The three-dimensional arrangement of the atoms within a molecule.

Molecular Angles

The angles formed between adjacent bonds in a molecule, which influence its three-dimensional shape and geometry.

• can affect the physical and chemical properties of a substance

  determined by factors such as the type of bonds (single, double, or triple)

• repulsion between electron pairs around the central atom, as described by VSEPR (Valence Shell Electron Repulsion) Theory

  Common molecular angles include 120° in trigonal planar geometry and 109.5° in tetrahedral arrangements.

Binary Acid

An acid composed of only two elements, typically hydrogen and a non-metal.

Structural Formula

A representation of a molecule that shows the arrangement of atoms and the bonds between them.

Endothermic Reaction

A reaction that absorbs energy from its surroundings, resulting in a temperature decrease.

Exothermic Reaction

A reaction that releases energy to its surroundings, often increasing the temperature.

Coordinate Covalent Bond

A type of bond where one atom provides both of the electrons shared in the bond.

Nonpolar Covalent Bond

A type of bond where electrons are shared equally between two atoms, resulting in no overall dipole.

Octet Rule Exceptions

Elements that do not require eight electrons to be stable, such as hydrogen, lithium, and boron.