single covalent bond
a bond formed when two atoms share a pair of electrons
structural formula
an expanded molecular formula showing the arrangement of atoms within the molecule
unshared pair
a pair of valence electrons that is not shared between atoms
double covalent bond
a bond in which two atoms share two pairs of electrons
triple covalent bond
a covalent bond in which three pairs of electrons are shared by two atoms
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
polyatomic ion
a covalently bonded group of atoms that has a positive or negative charge and acts as a unit
bond dissociation energy
the energy required to break the bond between two covalently bonded atoms
resonance structure
one of the two or more equally valid electron dot structures of a molecule or polyatomic ion
What electron configurations do atoms usually achieve by sharing electrons to form covalent bonds?
in covalent bonds, electron sharing usually occurs so that atoms attain the electron configurations of noble gases
How is an electron dot structure used to represent a covalent bond?
an electron dot structure such a H:H represents the shared pair of electrons of the covalent bond by two dots
When are two atoms likely to form a double bond between them? a triple bond?
Atoms form double or triple covalent bondsif they can attain a noble gas structure by sharing two pairs or three pairs of electrons
how is a coordinate covalent bond different from other covalent bonds?
in a coordinate covalent bond, the shared electron pair comes from one of the bonding atoms
List three ways in which the octet rule can sometimes fail to be obeyed
the actual bonding of oxygen atoms in ozone is a hybrid, or mixture, of the extremes represented by the resonance forms
What kinds of information does a structural formula reveal about the compound it represents?
it reveals where things are attached