Molecular geometry

Question 1

Electronegativity

Answer 1

This is the measure of the amount of attraction that an atom is able to exert upon a shared electron pair within a chemical bond

Question 2

VSEPR

Answer 2

Valence Shell Electron Pair Repulsion - there are numerous forces that exist with the molecule due to electron repulsions that occur as a result of the proximity of the bonding pairs and lone pair electrons within the individual atoms’ orbitals. These are called intramolecular repulsion forces or steric stresses.

Question 3

Lone pair to lone pair repulsions

Answer 3

Strong

Question 4

Lone pair to bond pair repulsions

Answer 4

Intermediate

Question 5

Bond pair to bond pair repulsions

Answer 5

Weak

Question 6

Angular

Answer 6

104,5-degree bond angle. Consists of 2 lone pairs that repel the 2 bond pairs with intermediate strength. Example: H2O (water)

2:2

Question 7

Pyramidal

Answer 7

107,3-degrees bond angle. Consists of 1 lone pair that repels the 3 bond pairs with accumulative strength.
Example: NH3 (ammonia)

3:1

Question 8

Tetrahedral

Answer 8

109-degrees bond angle. Consists of 4 bond pairs with the most steric stress in the molecule even though it has the lowest strength individually. Example: CH4 (methane)

4:0

Question 9

Linear

Answer 9

180-degree bond angle. Consists of 1 or 2 bond pairs. Typical in diatomic molecules. Examples: HF, HCL, HBr and HI.

1 or 2:0

Question 10

Trigonal planar

Answer 10

120-degree bond angle. Consists of 3 bond pairs. They are perfectly symmetrical. Example: BF3

3:0