Understanding Fire and Its Requirements
Fire is a chemical reaction known as combustion, which requires certain elements to ignite and sustain itself. The primary element needed for fire is oxygen.
Why Oxygen is Essential for Fire:
- Combustion Process:
- Fire occurs when a fuel (like wood or gasoline) reacts with oxygen in the air.
- This reaction releases heat and light, producing flames.
- Oxygen's Role:
- Oxygen supports the combustion process by reacting with the fuel.
- It helps break down the molecular structure of the fuel, leading to combustion.
- Chemical Reaction:
- The basic reaction involves fuel and oxygen combining to produce carbon dioxide, water, and energy (heat).
- Without adequate oxygen, the reaction cannot occur effectively.
Why Other Options Do Not Support Fire:
- Carbon Dioxide (b):
- Carbon dioxide is a byproduct of combustion and actually extinguishes flames by displacing oxygen.
- Nitrogen (c):
- Nitrogen is inert and does not participate in the combustion process, thus it does not support fire.
- Water Vapour (d):
- Water vapour can cool down flames and reduce oxygen availability, thereby hindering combustion.
Conclusion:
In summary, oxygen is vital for the burning of fire, as it is the key element that sustains the combustion reaction. Without oxygen, fire cannot exist, making it the correct answer to the question. Understanding this principle helps us appreciate the nature of fire and its requirements for survival.

Soil provides water and nutrients to the plant.