Shapes of simple molecules & ions

bonding pairs + lone (non-bonding) pairs of electrons as charge clouds

repel eachother

pairs of electrons in outer shell of atoms

arrange themselves as far apart as possible to minimise repulsion

lone pair - lone pair repulsion is … than lone pair - lone bond pair repulsion

greater

lone pair - lone bond pair repulsion is … than bond pair - bond pair repulsion

greater

shape of molecules is determined by →

no. of electron pairs around the central atom

each electron pair naturally repels eachother so →

largest bond angle possible exists between covalent bonds

lone pairs around central atom cause

additional repulsive forces, changing the bond angle

for every lone pair, bond angle between covalent bonds is reduced by

2.5 degrees

linear

2 bonding e- pairs

0 lone e pairs

180 degrees bond angle

V - shaped

2 bonding e- pairs

2 lone e- pairs

104.5 degrees

Trigonal Planar

3 bonding e- pairs

0 lone e- pairs

120 degrees

Triangular Pyramid

3 bonding e- pairs

1 lone e- pairs

107 degrees

Tetrahedral

4 bonding e- pairs

0 lone e- pairs

109.5 degrees

Trigonal Bipyramid

5 bonding e- pairs

0 lone e- pairs

90 + 120 degrees

Octahedral

6 bonding e- pairs

0 bonding e- pairs

90 degrees