Chapter 8: Basic Concepts of Chemical Bonding

Ionic Bond

An electrostatic attraction between ions, typically formed between metals and nonmetals.

Covalent Bond

A bond formed when nonmetals share electrons.

Octet Rule

A chemical rule that reflects the observation that atoms tend to bond in such a way that they each have eight electrons in their valence shell.

Lewis Symbols

Symbols that represent the valence electrons of an atom as dots surrounding the element's symbol.

Lone pairs

Electrons located on only one atom in a Lewis structure.

Bonding pairs

Shared electrons in a Lewis structure, represented by two dots or one line.

Electronegativity

The ability of an atom in a molecule to attract electrons to itself.

Non-polar covalent bond

A covalent bond where the electrons are shared equally.

Polar covalent bond

A covalent bond where the electrons are not shared equally, resulting in a dipole.

Dipole Moment (μ)

A measure of the separation of positive and negative charges in a molecule.

Formal Charge

The charge an atom would have if all electrons in a covalent bond were shared equally.

Resonance

The concept that some molecules can be represented by two or more structures that differ only in the placement of electrons.

Hypervalent

Referring to atoms that can accommodate more than eight electrons in their valence shell.

Localized electrons

Electrons that are specifically on one atom or shared between two atoms.

Delocalized electrons

Electrons that are spread over several atoms and can move around.

Electronegativity trend

Electronegativity increases from left to right and decreases from bottom to top on the periodic table.

Multiple Bonds

Bonds formed when atoms share more than one pair of electrons; includes single, double, and triple bonds.

Lewis Structure

A diagram that shows the arrangement of atoms and the distribution of electrons in a molecule.

Bound pairs

Pairs of electrons that are shared between atoms in a covalent bond, contributing to bond formation.

Octet exceptions

Ions or molecules that do not follow the octet rule, including those with odd electron counts, fewer or more than eight electrons.