Molecular shapes Flashcards
1
Q
What causes molecules to have a shape
A
According to VSPER, results from repulsion between groups of electrons, both bonding and nonbonding in the valence shell of the central atom
2
Q
What does optimum shape do
A
Allows for the valence shell electron groups around the central atom to have the greatest possible angle of separation. The shape depends on the number of groups. more crowded, angular separation decreases
3
Q
1-2 groups
A
linear, 180d bond angle
4
Q
3 groups with no lone pairs
A
triangulr planar- 120d
5
Q
4 groups with no lone pairs
A
tetrahedral-109.5 d
6
Q
4g 1lp
A
pyramidal- bond angles few degrees less than 109.5
7
Q
4g 2lp
A
bent- several degrees less than 109.5d
8
Q
If lone pairs
A
repulsion of lone pair in larger, actual bond angles reduced
