32 terms

Chemistry 521A - Chapter 8

an electrically neutral group of atoms joined together by covalent bonds
Molecular Compound
compound composed of molecules
Covalent Bond
joins atoms held together by sharing electrons
Diatomic molecule
a molecule composed of two atoms
Molecular formula
shows the kinds and numbers present in a molecule of a compound
Single Covalent Bond
a chemical bond in which only one pair of electrons is shared by two bonded atoms
Structural formula
a chemical formula that shows the arrangement of atoms in a molecule or polyatomic ion
bond dissociation energy
the amount of energy required to break a covalent bond between atoms
Polyatomic ion
a tightly bound group of atoms that has a positive or negative charge and behaves as a unit
Coordinate covalent bond
a covalent bond in which one atom contributes both bonding electrons
VESPR Theory
states that because electron pairs repel, molecules adjust their shapes so that valence-electron pairs are as far apart as possible
linear molecule
a term used to describe the shape of certain molecules such as CO2
sigma bond
a bond formed when two atomic orbitals combine to form a molecular orbital that is symmetrical along the axis connecting the two atomic nuclei
pi bond
a bond in which the bonding electrons are most likely to be found in the sausage-shaped regions above and below the nuclei of the bonded atoms
a process in which several atomic orbitals overlap to form the same number of equivalent hybrid orbitals
nonpolar covalent bond
a bond formed when the atoms in a molecule are alike and the bonding electrons are shared equally
polar covalent bond
a bond formed when two different atoms are joined by covalent bond and the bonding electrons are shared unequally
polar molecule
a molecule in which one end is slightly positive and the other is slightly negative
van der Waals forces
a term used to describe the weakest intermolecular attractions; these include dispersion forces and dipole interactions
network solid
a substance in which all of the atoms are covalently bonded to each other
double covalent bond
a bond in which two atoms share two pairs of electrons
dispersion force
attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces; they are the weakest interactions between molecules
triple covalent bond
a bond in which three pairs of electrons are shared by two atoms
hydrogen bond
attractive forces in which a hydrogen covalently bonded to a very electron negative atom is also weakly bonded to an unshared electron pair of another electronegative atom
resonance structure
one of the two or more equally valid electron dot structures of a molecule or a polyatomic ion
a molecule that has two poles or regions with opposite charges
unshared pairs
a pair of valence electrons that is not shared between atoms
a relative measure of an atom's ability to attract the shared electrons in a chemical bond
bond energy
the amount of energy required to break a specific bond in one mole of molecule, given in kJ/mole
valence electrons
an electron that occupies the outermost energy level or shell of an atom
Lewis Structures
a symbolic representation of the arrangement of the valence electrons of an element or compound
octet rule
states that when bonds form, atoms gain, lose or share electrons in such as way as to achieve an octet or filled energy level