shapes and polarity (chem test 2)

2 electron groups

linear 

linear bond angle

180

3 electron group (all atoms)

trigonal planar

trigonal planar angle

120

3 electron group (1 lone pair)

bent

bent angle

< 120

4 electron group (all atoms)

tetrahedral

tetrahedral angle

109.5

4 electron groups (1 lone pair)

trigonal pyramidal

trigonal pyramidal angle

< 109.5

4 electron groups (2 lone pair)

bent

bent (2 lone pair) angle

< 109.5

< 0.5

nonpolar bond

0.5 and lower than 2.0

polar bond

all nonpolar bonds =

nonpolar molecule

1 polar bond =

polar molecule 

e.g = identical polar bonds

nonpolar molecule

e.g does NOT = identical polar bonds 

polar molecule