Tetrahedral with angles of 109.5°

Exceptions to the "Octet Rule."

 To help determine if the octet rule is followed recall Clark's Method (abbreviated) for determining bonding in covalent Lewis Structures: Add up all of the valence electrons in the structure (remember to add one electron for each negative charge, or subtract one for each positive charge) If e- = 6y + 2 where y = # atoms other than H, then octet rule is followed with single bonds only. If e- < 6y + 2 then probably have multiple bonding with the number of multiple bonds = /2 (remember a triple bond is 2 multiple bonds!). However, note the exceptions below with small atoms (H, Li, Be, and B). If e- > 6y + 2 then have an expanded valence shell. Note that if = 2, then pentavalent (10 electrons in the valence shell) , and if = 4, then hexavalent (12 electrons in the valence shell). If you can draw more than one structure, then chose the most symmetrical. If two or more structures are equally symmetrical, then you probably have resonance and should show all structures connected by double arrows.

Trigonal bipyramidal with angles of 90° & 120° (PCl5)

Seesaw with angles of 90° & 120° (SF4)

T-shaped with angles of 90° (ClF3)

Linear with angles of 180° (I3-)

Octahedral with angles of 90° (AsF6-)

Tetragonal pyramidal with angles of 90° (ICl5)

Square planar with angles of 90° (XeF4)