Air is a ________.

The correct answer is Mixture of gases.

Key Points

• Air is a mixture of gases that primarily consists of nitrogen (78%), oxygen (21%), and other gases such as carbon dioxide, argon, and trace gases.
• The composition of air can vary slightly depending on the altitude, location, and environmental factors.
• Air also contains water vapor, with its percentage varying based on humidity and temperature conditions.
• Unlike a chemical compound, air is not chemically bonded; instead, its gases coexist in a physical mixture.
• The presence of nitrogen and oxygen in air is essential for supporting life processes such as respiration and combustion.

Additional Information

• Composition of Air:
  • Air contains approximately 78% nitrogen, 21% oxygen, and 1% argon and other trace gases.
  • Carbon dioxide constitutes about 0.04%, and its concentration has increased due to human activities.
  • Water vapor in air varies from 0% to 4%, depending on humidity levels.
• Terminology:
  • Mixture: A physical combination of two or more substances that retain their individual properties.
  • Trace Gases: Gases present in very small amounts, such as neon, helium, methane, and krypton.
• Role of Air in Life Processes:
  • Oxygen is crucial for respiration in humans, animals, and plants.
  • Carbon dioxide is utilized by plants during photosynthesis to produce oxygen and glucose.
  • Nitrogen plays a role in the nitrogen cycle, which is vital for soil fertility and plant growth.
• Air Pollution:
  • Contaminants such as particulate matter, carbon monoxide, sulfur dioxide, and nitrogen oxides can degrade air quality.
  • Common sources of air pollution include industries, vehicles, burning fossil fuels, and deforestation.