bonding: lewis structures, the octet rule, and exceptions

valence electrons

number of outermost electrons in the outermost shell. indicated by group number.

lewis structure

two-dimensional model, represents covalent/ionic bonds as straight lines and unbonded valence electrons as dots

covalent bond

share electrons. sharing creates a bond between the elements

ionic bonds

cation give anion electrons. between metals and non-metals

lone pairs

pairs of electrons only attached to one atom

octet rule

need 8 electrons to fill outermost shell and be stable. exceptions are hydrogen can only have 2 electrons in outermost shell, and Be, B, and third period and beyond have more than 8 electrons in outermost shell

double bond

bond in which 2 pairs of electrons are shared by a pair of electrons

triple bond

bond in which 3 pairs of electrons are shared by a pair of electrons