Explanation

• O₃ is the chemical formula of ozone gas.
• Ozone is an allotrope of oxygen containing three oxygen atoms.
• It is mainly found in the stratosphere, where it forms the ozone layer.
• The ozone layer protects Earth from harmful ultraviolet (UV) radiation.

Last verified on 30-06-2026

Explanation

• Nitrogen (N₂) → 78%

Additional information:

• Oxygen (O₂) → 21%
• Argon (Ar) → 0.93%
• Carbon dioxide (CO₂) → 0.04% (approximately)
• Other gases → Trace amounts

Last verified on 28-06-2026

Explanation

• CFCs, carbon dioxide (CO₂), and methane (CH₄) are all greenhouse gases.
• Carbon dioxide traps heat in the atmosphere and increases temperature.
• Methane is a very strong greenhouse gas with high warming effect.
• CFCs also damage the ozone layer and act as greenhouse gases.

Last verified on 16-06-2026

Explanation

• The atmosphere is an open system.
• Because it exchanges both matter and energy with surroundings.
• Gases like oxygen, carbon dioxide, and water vapour continuously move in and out.
• Energy from the Sun enters and heat is also released back into space.
• This continuous exchange keeps atmospheric processes active.

Last verified on 16-06-2026

Explanation

• The ecosystem is the structural and functional unit of the environment.
• Ecosystem = Biotic + Abiotic components
• Biotic: plants, animals, microorganisms
• Abiotic: water, air, soil, sunlight

Last verified on 08-06-2026