The number of greenhouse gases of the following is ________.
`CO_(2), O_(2),N_(2)O, CH_(4), CFCs, CO, H_(2)O (g), O_(3)`

Answer

To determine the number of greenhouse gases from the given list, we need to identify which of the gases are classified as greenhouse gases. Greenhouse gases are those that trap heat in the atmosphere, allowing sunlight to enter but preventing some of the heat from escaping.

Let's analyze each gas in the list:

1. **CO₂ (Carbon Dioxide)**: This is a well-known greenhouse gas that contributes to the greenhouse effect.
- **Hint**: Remember that CO₂ is produced from burning fossil fuels and is a significant contributor to global warming.

2. **O₂ (Oxygen)**: This gas is essential for life but does not trap heat in the atmosphere.
- **Hint**: Consider the role of oxygen in respiration and combustion, but not in heat retention.

3. **N₂O (Nitrous Oxide)**: This is a greenhouse gas that has a much higher heat-trapping ability than CO₂.
- **Hint**: Think about agricultural practices and their contribution to nitrous oxide emissions.

4. **CH₄ (Methane)**: This is a potent greenhouse gas, significantly more effective at trapping heat than CO₂.
- **Hint**: Remember that methane is released from livestock, landfills, and natural gas production.

5. **CFCs (Chlorofluorocarbons)**: These are man-made greenhouse gases that were commonly used in refrigeration and aerosol propellants.
- **Hint**: CFCs are known for their role in ozone depletion as well.

6. **CO (Carbon Monoxide)**: This gas is not considered a greenhouse gas as it does not significantly contribute to the greenhouse effect.
- **Hint**: Consider the sources of carbon monoxide and its effects on health rather than climate.

7. **H₂O (Water Vapor)**: Water vapor is the most abundant greenhouse gas in the atmosphere and plays a crucial role in the greenhouse effect.
- **Hint**: Water vapor is naturally occurring and varies with temperature.

8. **O₃ (Ozone)**: Ozone in the stratosphere protects us from UV radiation, but ozone at ground level is a greenhouse gas.
- **Hint**: Differentiate between stratospheric ozone and tropospheric ozone in terms of their effects.

Now, let's count the greenhouse gases from the list:

- CO₂: Greenhouse gas
- O₂: Not a greenhouse gas
- N₂O: Greenhouse gas
- CH₄: Greenhouse gas
- CFCs: Greenhouse gas
- CO: Not a greenhouse gas
- H₂O: Greenhouse gas
- O₃: Greenhouse gas

Counting the greenhouse gases, we find:

1. CO₂
2. N₂O
3. CH₄
4. CFCs
5. H₂O
6. O₃

Thus, the total number of greenhouse gases in the list is **6**.

**Final Answer**: The number of greenhouse gases of the following is **6**.

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