Which of the following is not a greenhouse gas ?

Options

A. `CH_(4)`
B. `O_(2)`
C. CFC
D. `N_(2)O`

Answer

To determine which of the following is not a greenhouse gas, let's analyze each option provided:

1. **CH4 (Methane)**: Methane is a well-known greenhouse gas. It is produced from various sources, including natural processes and human activities, and it contributes significantly to the greenhouse effect.

2. **O2 (Oxygen)**: Oxygen is essential for life and is a major component of the Earth's atmosphere. However, it does not trap heat in the atmosphere and therefore is not considered a greenhouse gas.

3. **CFC (Chlorofluorocarbons)**: CFCs are synthetic compounds that have been used in refrigeration, air conditioning, and aerosol propellants. They are potent greenhouse gases and contribute to ozone depletion.

4. **N2O (Nitrous Oxide)**: Nitrous oxide is another important greenhouse gas that is emitted from agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.

Now, let's summarize the analysis:

- **Greenhouse Gases**: CH4 (Methane), CFC (Chlorofluorocarbons), N2O (Nitrous Oxide)
- **Not a Greenhouse Gas**: O2 (Oxygen)

Therefore, the correct answer to the question "Which of the following is not a greenhouse gas?" is **O2 (Oxygen)**.