Which one of the following gases is known as chemical weed in troposphere?

Options

A. `C_(2)H_(6)`
B. `SO_(2)`
C. `O_(3)`
D. `NO_(2)`

Answer

To solve the question "Which one of the following gases is known as chemical weed in troposphere?", we can follow these steps:

### Step 1: Understand the term "chemical weed"
- The term "chemical weed" refers to an undesirable or unwanted gas that has harmful effects on the environment and living organisms.

### Step 2: Analyze the options given
- The options provided are:
- A) C2H6 (Ethane)
- B) SO2 (Sulfur Dioxide)
- C) O3 (Ozone)
- D) NO2 (Nitrogen Dioxide)

### Step 3: Identify the characteristics of each gas
- **C2H6 (Ethane)**: This is a hydrocarbon and is not typically classified as a harmful gas in the troposphere.
- **SO2 (Sulfur Dioxide)**: This gas is known for its role in air pollution and acid rain but is not specifically referred to as a "chemical weed."
- **O3 (Ozone)**: Ozone at ground level (troposphere) is considered a harmful pollutant and is formed by chemical reactions involving other pollutants. It is often referred to as a "chemical weed" due to its negative effects on health and the environment.
- **NO2 (Nitrogen Dioxide)**: This gas is also a pollutant but does not carry the specific label of "chemical weed."

### Step 4: Conclude based on harmful effects
- Ozone (O3) is known to have several harmful effects, such as:
- Acting as an air pollutant.
- Preventing sunlight from reaching plants, thus damaging them.
- Having adverse effects on human health.

### Final Answer
- Based on the analysis, the gas known as "chemical weed" in the troposphere is **C) O3 (Ozone)**.

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