Which of the following molecules or ions is not linear?

Options

A. `BeCl_(2)`
B. `I_(3)^(-)`
C. `CS_(2)`
D. `I Cl_(2)^(+)`

Explanation

To determine which of the following molecules or ions is not linear, we will analyze the molecular geometry of each option provided.

### Step-by-Step Solution:

1. **Identify the Molecules/Ions**: We need to analyze the molecular geometry of the following species:
- BeCl₂ (Beryllium dichloride)
- I₃⁻ (Triiodide ion)
- C=S (Carbon disulfide)
- ICl₂⁺ (Iodine dichloride cation)

2. **Analyze BeCl₂**:
- Beryllium (Be) has 2 valence electrons and forms 2 bonds with chlorine (Cl), which has 7 valence electrons.
- The Lewis structure shows 2 bond pairs and 0 lone pairs.
- The steric number is 2 (bond pairs) + 0 (lone pairs) = 2.
- Hybridization is sp, leading to a linear shape.

3. **Analyze I₃⁻**:
- Iodine (I) has 7 valence electrons, and with one negative charge, it has a total of 8 valence electrons.
- The Lewis structure shows 2 bond pairs and 3 lone pairs.
- The steric number is 2 (bond pairs) + 3 (lone pairs) = 5.
- The hybridization is sp³d, and the shape is linear due to the arrangement of the lone pairs in the equatorial position.

4. **Analyze C=S**:
- Carbon (C) forms a double bond with sulfur (S).
- The Lewis structure shows 2 bond pairs (from the double bond) and 0 lone pairs.
- The steric number is 2 (bond pairs) + 0 (lone pairs) = 2.
- Hybridization is sp, leading to a linear shape.

5. **Analyze ICl₂⁺**:
- Iodine (I) has 7 valence electrons, and with a positive charge, it has 6 valence electrons.
- The Lewis structure shows 2 bond pairs and 2 lone pairs.
- The steric number is 2 (bond pairs) + 2 (lone pairs) = 4.
- The hybridization is sp³, leading to a bent shape due to the presence of lone pairs.

6. **Conclusion**:
- The only molecule that is not linear is **ICl₂⁺**, which has a bent shape due to the presence of lone pairs.

### Final Answer:
The molecule that is not linear is **ICl₂⁺**.