29 terms

Chemistry Ch. 8-Covalent Bonding

covalent bond
joining of atoms held together by sharing electrons
a neutral group of atoms joined together by covalent bonds
diatomic molecule
a molecule consisting of two atoms
molecular compound
a compound composed of molecules
molecular formula
the chemical formula of a molecular compound
single covalent bond
two atoms held together by sharing a pair of electrons
structural formula
represents the covalent bonds by dashes and shows the arrangement of covalently bonded atoms
unshared pair
a pair of valence electrons that is not shared between atoms
double covalent bond
a bond that involves two shared pairs of electrons
triple covalent bond
a bond formed by sharing three pairs of electrons
coordinate covalent bond
a covalent bond in which one atom contributes both bonding electrons
polyatomic ion
a tightly bound group of atoms that has a positive or negative charge and behaves as a unit
bond dissociation energy
the energy required to break the bond between two covalently bonded atoms
resonance structure
the structure that occurs when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion
molecular orbitals
orbitals that apply to the entire molecule
bonding orbital
a molecular orbital that can be occupied by two electrons of a covalent bond
sigma bond
a bond formed when two atomic orbitals form a molecular orbital that is symmetrical around the axis connecting two atomic nuclei
pi bond
a covalent bond in which the bonding electrons are most likely to be found in sausage-shaped regions above and below the bond axis of the bonded atoms
tetrahedral angle
a bond angle of 109.5 that results when a central atom forms four bonds directed toward the center of a regular tetrahedron
VSEPR theory
because electron pairs repel, molecules adjust their shapes so that valence electron pairs are as far apart as possible
the mixing of several atomic orbitals to form the same total number of equivalent hybrid orbitals
nonpolar covalent bond
a covalent bond in which the electrons are shared equally by the two atoms
polar covalent bond
a covalent bond between atoms in which the electrons are shared equally
a molecule that has two poles, or regions, with opposite charges
van der waals force
the two weakest intermolecular attractions-dispersion interactions and dipole forces
dipole interactions
intermolecular forces resulting from the attraction of oppositely charged regions of polar molecules
dispersion forces
attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces; these are the weakest interactions between molecules
hydrogen bond
attractive forces in which a hydrogen covalently boned to a very electronegative atom is also weakly bonded to an unshared pair of another electronegative atom
network solid
a solid in which all of the atoms are covalently bonded to each other