The linear struture is assumed by :

Options

A. `SnCI_(2)`
B. `CS_(2)`
C. `NO_(2)^(o+)`
D. `NCO^(Theta)`

Explanation

To determine which of the compounds has a linear structure, we will analyze each compound one by one based on their molecular geometry.

### Step-by-Step Solution:

1. **Understanding Linear Structure**:
- A linear structure occurs when the atoms are arranged in a straight line, resulting in a bond angle of 180 degrees. This typically happens in molecules with the general formula AB2, where A is the central atom and B represents the surrounding atoms.

2. **Analyzing SnCl2**:
- **Lewis Structure**: SnCl2 has a central tin (Sn) atom bonded to two chlorine (Cl) atoms.
- **Lone Pairs**: Tin has one lone pair of electrons.
- **Molecular Geometry**: The presence of the lone pair distorts the bond angle from 180 degrees to about 95 degrees, resulting in a bent structure rather than a linear one.
- **Conclusion**: SnCl2 does not have a linear structure.

3. **Analyzing CS2**:
- **Lewis Structure**: CS2 consists of a central carbon (C) atom bonded to two sulfur (S) atoms.
- **Molecular Geometry**: There are no lone pairs on the carbon atom, and the bond angle is 180 degrees.
- **Conclusion**: CS2 has a linear structure.

4. **Analyzing NO2+ (Nitronium Ion)**:
- **Lewis Structure**: NO2+ has a nitrogen (N) atom bonded to two oxygen (O) atoms.
- **Molecular Geometry**: The ion is isoelectronic with CS2, and the structure is linear with a bond angle of 180 degrees.
- **Conclusion**: NO2+ has a linear structure.

5. **Analyzing NCO- (Cyanate Ion)**:
- **Lewis Structure**: NCO- has a nitrogen (N) atom bonded to a carbon (C) atom, which is then bonded to an oxygen (O) atom.
- **Molecular Geometry**: The presence of the negative charge does not affect the linear arrangement, and it maintains a bond angle of 180 degrees.
- **Conclusion**: NCO- has a linear structure.

### Final Conclusion:
The compounds that exhibit a linear structure are:
- CS2
- NO2+
- NCO-