Which of the following is greenhouse gas?

Options

A. `CH_(4)`
B. `H_(2)`
C. `O_(3)`
D. All of these

Answer

To determine which of the following is a greenhouse gas, we need to analyze each option provided:

1. **Option A: CH4 (Methane)**
- Methane (CH4) is a hydrocarbon and a significant component of natural gas. It is known to be a greenhouse gas because it has the ability to trap heat in the atmosphere, contributing to the greenhouse effect. Methane is actually over 25 times more effective than carbon dioxide (CO2) at trapping heat in the atmosphere over a 100-year period. Therefore, CH4 is indeed a greenhouse gas.

2. **Option B: H2 (Hydrogen)**
- Hydrogen (H2) is not considered a greenhouse gas. While it is an important fuel and energy carrier, it does not have the capability to trap heat in the atmosphere like greenhouse gases do. Therefore, H2 is not a greenhouse gas.

3. **Option C: O3 (Ozone)**
- Ozone (O3) exists in two layers of the atmosphere: the stratosphere and the troposphere. While ozone in the stratosphere protects us from harmful ultraviolet (UV) radiation, ozone in the troposphere is a pollutant and contributes to global warming. However, it is not classified as a greenhouse gas in the same way that CO2 or CH4 are. Thus, O3 is not primarily considered a greenhouse gas.

4. **Option D: All of these**
- Since both H2 and O3 are not greenhouse gases, the option "All of these" cannot be correct.

Based on the analysis, the only greenhouse gas among the options provided is **CH4 (Methane)**.

**Final Answer:** CH4 (Methane) is the greenhouse gas.