Give the shapes associated with the following molecules
`(i)AB_(3)(ii)AB_(4)(iii)AB_(5).`

Answer

To determine the shapes associated with the molecules AB₃, AB₄, and AB₅, we can use the VSEPR (Valence Shell Electron Pair Repulsion) theory. This theory helps us predict the geometry of molecules based on the number of bonding pairs and lone pairs of electrons around the central atom.

### Step-by-Step Solution:

1. **Identify the number of bonding pairs and lone pairs:**
- For AB₃: There are 3 bonding pairs and 0 lone pairs.
- For AB₄: There are 4 bonding pairs and 0 lone pairs.
- For AB₅: There are 5 bonding pairs and 0 lone pairs.

2. **Determine the molecular geometry for each molecule:**
- **For AB₃:**
- The central atom A is bonded to 3 B atoms.
- With no lone pairs, the shape is determined by the arrangement of the 3 bonding pairs.
- The geometry is **trigonal planar**.

- **For AB₄:**
- The central atom A is bonded to 4 B atoms.
- Again, with no lone pairs, the shape is determined by the arrangement of the 4 bonding pairs.
- The geometry is **tetrahedral**.

- **For AB₅:**
- The central atom A is bonded to 5 B atoms.
- With no lone pairs, the shape is determined by the arrangement of the 5 bonding pairs.
- The geometry is **trigonal bipyramidal**.

3. **Summarize the shapes:**
- AB₃: Trigonal planar
- AB₄: Tetrahedral
- AB₅: Trigonal bipyramidal

### Final Answer:
- The shapes associated with the molecules are:
- (i) AB₃: Trigonal planar
- (ii) AB₄: Tetrahedral
- (iii) AB₅: Trigonal bipyramidal