14 terms

Chem- ch. 8

covalent bond
a chemical bond that results from the sharing of valence electrons
endothermic reaction
a chemical reaction or process in which a greater amount of energy is required to break the existing bonds in the reactants that is released when the new bonds form in the product molecules
exothermic reaction
a chemical reaction or process in which more energy is realeased than is required to break bonds in the initial reactions
lewis structure
a model that uses electron-dot structures to show how electrons are arranged in molecules. Pairs of dots or lines represent bonding pairs.
forms when two or more atoms covalently bond and is lower in potential energy than its consitituent atoms
pi bond
a bond that is formed when parallel orbitals overlap to share electrons
sigma bond
a single covalent bond that is formed when an electron pair is shared by the direct overlap of bonding orbitals
any acid that contains hydrogen and an oxyanion
coordinate covalent bond
forms when one atom donates a pair of electrons to be shared with an atom or ion that needs two electrons to become stable
condition that occurs when more than one valid lewis structure exists for the same molecule
structural formula
a molecular model that uses symbols and bonds to show relative positions of atoms; can be predicted for many molecules by drawing the lewis structure
a process in which atomic orbitals are mixed to form new, identical hybrid orbitals
VSEPR model
Valence Shell Electron Pair Repulsion model, which is based on an arrangement that minimizes the repulsion of shared and unshared pairs of electrons around the central atom
polar covalent bond
a type of bond that forms when electrons are not shared equally