coordinate covalent bond 

can share an entire pair of electrons donated by another atom. When one atom donates a pair of electrons to be shared with an atom or ion that needs two electrons to become stable

covalent bond 

 The chemical bond that results from the sharing of valence electrons

(A nonmetal and a nonmetal)

molecule 

formed when two or more atoms bond covalently

 oxyacid

 Any acid that contains hydrogen and an oxyanion

 pi bond 

formed when parallel orbitals overlap to share electrons

 polar covalent

 Unequal sharing

 a condition that occurs when more than one valid Lewis structure can be written for a molecule or ion. The two or more cor- rect Lewis structures that represent a single molecule or ion are often referred to as resonance structures.

 Single covalent bonds; occurs when the electron pair is shared in an area centered between the two atoms. When two atoms share electrons, the valence atomic orbital of one atom overlaps or merges with the valence atomic orbital of the other atom

 uses letter symbols and bonds to show relative positions of atoms

 model used to determine the molecular shape is referred to as the Valence Shell Electron Pair Repulsion model; based on an arrangement that minimizes the repulsion of shared and unshared pairs of electrons around the central atom

endothermic 

reactions occur when a greater amount of energy is required to break the existing bonds in the reactants than is released when the new bonds form in the product molecules

 exothermic (p. 247) •

 reactions occur when more energy is released forming new bonds than is required to break bonds in the initial reactants

 hybridization

carbon atoms undergo; a process in which atomic orbitals are mixed to form new, identical hybrid orbitals