Chapter 4: Chemical Bonding- Understanding Climate Change

electronegativity 

A relative measure of an atom's ability to attract electrons to itself within a bond.

electropositive

Describing an atom that has little tendency to attract valence electrons to itself within a bond.

electrostatic potential energy

(E_el) The energy a charged particle has because of its position relative to another charged particle; E_el is directly proportional to the product of the charges of the particles and inversely proportional to the distance between them; also called coulombic attraction.

ionic bond

A bond resulting from the electrostatic attraction of a cation to an anion.

crystal lattice

An ordered three-dimensional array of particles.

lattice energy

(U) The energy released when 1 mole of an ionic compound forms from its free ions in the gas phase.

covalent bonds

A bond created by two atoms sharing one or more pairs of electrons.

nonpolar covalent bond

A bond characterized by an even distribution of charge; the two atoms equally share the electrons in the bond.

bond length

The distance between the nuclei of two atoms joined in a bond.

bond energy

The energy needed to break 1 mole of a specific covalent bond in the gas phase; also called bond strength.

polar covalent bond

A bond resulting from unequal sharing of pairs of electrons between atoms.

dipole

A pair of oppositely charged poles separated by a distance.

metallic bond

A bond consisting of the nuclei of metal atoms surrounded by a "sea" of shared electrons.

polyatomic ion

A charged group of atoms joined by covalent bonds.

oxoanion

A polyatomic anion that contains at least one nonoxygen central atom bonded to one or more oxygen atoms.

oxoacid

A compound composed of oxoanions bonded to H⁺ ions.

octet rule

The tendency of atoms of main group elements to make bonds by gaining, losing, or sharing electrons to achieve a valence shell containing eight electrons, or four electron pairs.

lewis symbol

The chemical symbol for an element surrounded by one or more dots representing valence electrons; also called a Lewis dot symbol.

bonding capacity

The number of covalent bonds an atom typically forms to have an octet of electrons in its valence shell.

lewis structure

A two-dimensional representation of the bonds and lone pairs of valence electrons in an ionic or molecular compound.

bonding pair

A pair of electrons that two atoms share.

single bond

A bond that results when two atoms share one pair of electrons.

lone pair

A pair of electrons not shared.

double bond

A bond formed when two atoms share two pairs of electrons.

triple bond

A bond formed when two atoms share three pairs of electrons.

bond order 

The number of bonds between atoms: 1 for a single bond, 2 for a double bond, and 3 for a triple bond.

allotropes

Different molecular forms of the same element, such as oxygen (O₂) and ozone (O₃).

resonance

A characteristic of electron distributions in which two or more equivalent Lewis structures can be drawn for one compound.

resonance structure

One of two or more Lewis structures with the same arrangement of atoms but different arrangements of bonding pairs of electrons.

electron-pair delocalization

The spreading out of electron density over several atoms.

resonance stabilization

The stability of a molecular structure resulting from the delocalization of its electrons.

formal charge

(FC) The value calculated for an atom in a molecule or polyatomic ion by determining the difference between the number of valence electrons in the free atom and the sum of the lone-pair electrons plus half the electrons in the atom's bonding pairs.

free radical

An atom, ion, or molecule with unpaired electrons.