Valency of sulphur atom in `SO_(2)` is:

Options

A. 3
B. 2
C. 4
D. 6

Answer

To determine the valency of the sulfur atom in sulfur dioxide (SO₂), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Compound**: We are given the compound sulfur dioxide, which is represented as SO₂.

2. **Understand Valency**: Valency refers to the combining capacity of an atom, which is determined by the number of electrons an atom can lose, gain, or share when forming chemical bonds.

3. **Determine the Charge of Oxygen**: In the compound SO₂, there are two oxygen atoms. Each oxygen atom typically has a valency of -2. Therefore, the total negative charge contributed by the two oxygen atoms is:
\[ \text{Total charge from oxygen} = 2 \times (-2) = -4 \]

4. **Establish the Neutrality of the Compound**: Since the compound is neutral, the total positive charge must equal the total negative charge. Thus, the positive charge from sulfur must balance the -4 charge from the two oxygen atoms.

5. **Calculate the Required Charge for Sulfur**: To balance the -4 charge from oxygen, sulfur must have a charge of +4:
\[ \text{Charge from sulfur} = +4 \]

6. **Determine the Valency of Sulfur**: The valency of sulfur is equal to the magnitude of the charge it carries when it combines with oxygen. Since sulfur has a charge of +4, its valency is:
\[ \text{Valency of sulfur} = 4 \]

### Conclusion:
Thus, the valency of the sulfur atom in SO₂ is 4.