Chemical bond
a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
Ionic bonding
chemical bonding that results from the electrical attraction between cations and anions
electrons are transferred from one atom to another
Covalent bonding
the sharing of electron pairs between two atoms
Nonpolar-covalent bond
a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balance distribution of electrical charge
electronegativity difference: 0 to 0.3
Polar
bonds that have an uneven distribution of charge with significantly different electronegativities
Polar-covalent bond
a covalent bond in which the bonded atoms have an unequal attraction for the shared electrons
electronegativity difference: 0.3 to 1.7
Molecule
a neutral group of atoms that are held together by covalent bonds
molecular compound
a chemical compound whose simplest units are molecules
chemical formula
the relative number of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts
molecular formula
the types and numbers of atoms combined in a single molecule of a molecular compound
diatomic molecule
a molecule containing only two atoms
Bond energy
the energy required to break a chemical bond and form neutral isolated atoms
Octet Rule
chemical compound ten to form so that each atom, by gaining, losing, or sharing electrons, has an octet of electrons in its highest occupied energy level
Exceptions to the Octet Rule and
Expanded Valence
hydrogen and boron (can have less then eight valence electrons)
expanded valence: elements that can have more then eight valence electrons
ex. fluorine, oxygen, and chlorine
Electron-dot notation
an electron-configuration notation in which only the valence electrons of an atom of a particular element are shown, indicated by dots placed around the element's symbol
Lone pair (unshared pair)
pairs of electrons that are not shared in bonds
Lewis Structures
formulas in which atomic symbols represent nuclei and inner-shell electrons, dot-pairs, or dashes between two atomic symbols represent electron pairs in covalent bonds and dots adjacent to only one atomic symbol represent unshared electrons
Structural Formula
the kind, number, arrangement, and bonds but not the unshared pairs of the atoms in a molecule
Single bond
a covalent bond in which one pair of electrons is shared between two atoms
Double bond
a covalent bond in which two pairs of electrons are shared between two atoms :: =
Triple bond
a covalent bond in which three pairs of electrons are shared between two atoms ::: ?
Multiple bonds
double and triple bonds
Resonance
(Resonance structure or resonance hybrids)
bonding in molecules or ions that cannot be correctly represented by a single Lewis structure
O=O-O ??? O-O=O (these two oxygen-oxygen structures are actually in real life a single structure that is an average of these two structures)
Ionic Compound
composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal
Formula Unit
the simplest collection of atoms which an ionic compound's formula can be established
Crystal Lattice
ions in an ionic crystal minimize their potential energy by combining in an orderly arrangement
Lattice Energy
the energy released when one mole of an ionic crystalline compound is formed from gaseous ions (negative energy values indicate the energy that is released when the crystals are formed)
Polyatomic ion
a charged group of covalently bonded atoms
Metallic bonding
the chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons
Malleability
the ability of a substance to be hammered or beaten into thin sheets
Ductility
the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire
Enthalpy of Vaporization
the amount of energy absorbed as heat when a specific amount of a substance vaporizes at a constant pressure
molecular polarity
the uneven distribution of molecular charge (it strongly influences the forces that act between molecules in liquids and solids)
VSEPR theory
valence-shell, electron-pair repulsion"
repulsion between the sets of valence-level electrons surrounding an atom causes these sets to be oriented as far apart as possible
Hybridization
the mixture of two or more atomic orbitals of similar energies on the same atom to produce new hybrid atomic orbitals of equal energies
Hybrid orbitals
orbitals of equal energy produced by the combination of two or more orbitals on the same atom
Intermolecular forces
the forces of attraction between molecule (they're generally weaker the bonds that join atoms in molecules, ions in ionic compounds, or metal atoms in solid metals)
Dipole
created by equal but opposite charges that are separated by a short distance
dipole-dipole forces
the forces of attraction between polar molecules (these forces are shot-range forces, action only between nearby molecules)
Hydrogen bonding
the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule (usually represented by dotted lines connecting the hydrogen-bo
London dispersion forces
the intermolecular attraction resulting from the constant motion of electron and the creation of instantaneous dipoles