lithium: attain 2 valence electrons

beryllium: attain 4 valence electrons

boron: bonds to attain 6 valence electrons

elements in period 3 and below: expand valence shell to include more than 8 electrons by incorporating d subshell orbitals

one or more electrons from an atom with lower ionization energy are transferred to an atom with greater electron affinity and the electrostatic force of attraction between opposite charges holds the resulting ions together

difference in electronegativities must be greater than 1.7

usually occurs between Group 1 or Group 2 and Group 7

very high melting and boiling points: because of the strength of electrostatic forces between ionic constituents of the compound

dissolve readily in polar solvents (aqueous); in molten or aqueous state = good conductors

solid state: form a crytallin lattice in which attractive forces between opposite charges are maximized and repulsive forces between ions of like chargers are minimized

an electron pair is shared betwen 2 atoms which have relatively similar values of electronegativity

binding force between the atoms is the attraction that each electron in the shared pair has for the 2 positive nuclei of the bonded atoms

lower melting and boiling points: because weak intermolecular interactions

poor conductors of electricity: because they don't break down into constituent ions

single bond: longest and weakest

triple bond: shortest and strongest

atoms of elements that differ moderately in their electronegativities will share their electrons unevenly

difference in electronegativities: between 0.4 - 1.7

vector quantity defined as the product of the charge magnitude and the distance between the 2 partial charges

μ = qr