The lead chamber process involves oxidation of `SO_2` by atomic oxygen under the influence of ____as catalyst.

Explanation

To solve the question regarding the lead chamber process and the catalyst involved in the oxidation of \( SO_2 \) by atomic oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Lead Chamber Process**: The lead chamber process is an industrial method used to produce sulfuric acid. It involves the oxidation of sulfur dioxide (\( SO_2 \)) to sulfur trioxide (\( SO_3 \)).

2. **Identify the Reactants**: In this process, sulfur dioxide (\( SO_2 \)) is oxidized. The reaction involves \( SO_2 \) reacting with oxygen (\( O_2 \)).

3. **Determine the Role of the Catalyst**: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. In the lead chamber process, the oxidation of \( SO_2 \) requires a catalyst.

4. **Identify the Catalyst Used**: The catalyst that facilitates the oxidation of \( SO_2 \) in the lead chamber process is nitrogen dioxide (\( NO_2 \)). This compound helps in the conversion of \( SO_2 \) to \( SO_3 \).

5. **Write the Overall Reaction**: The overall reaction can be summarized as:
\[ 2 SO_2 + O_2 \xrightarrow{NO_2} 2 SO_3 \]

6. **Final Answer**: Therefore, the lead chamber process involves the oxidation of \( SO_2 \) by atomic oxygen under the influence of \( NO_2 \) as a catalyst.

### Final Answer:
The lead chamber process involves oxidation of \( SO_2 \) by atomic oxygen under the influence of **\( NO_2 \)** as catalyst.