Question

h
|
h - al - h
|
h

h
|
:f - c - f:
|
h

h - p - h
|
h

:ö=ö - ö:

Explanation:

Step1: Determine central atom in AlH₄⁻

Al is central atom with 4 bonding pairs and 0 lone - pairs.

Step2: Apply VSEPR theory

For 4 bonding pairs and 0 lone - pairs, shape is tetrahedral.

Step3: Determine central atom in CH₂F₂

C is central atom with 4 bonding pairs and 0 lone - pairs.

Step4: Apply VSEPR theory

For 4 bonding pairs and 0 lone - pairs, shape is tetrahedral.

Step5: Determine central atom in PH₃

P is central atom with 3 bonding pairs and 1 lone - pair.

Step6: Apply VSEPR theory

For 3 bonding pairs and 1 lone - pair, shape is trigonal - pyramidal.

Step7: Determine central atom in O₃

One of the O atoms is central with 2 bonding pairs and 1 lone - pair.

Step8: Apply VSEPR theory

For 2 bonding pairs and 1 lone - pair, shape is bent.

Answer:

1. tetrahedral
2. tetrahedral
3. trigonal - pyramidal
4. bent