Explanation

• Relief rainfall is also known as orographic rainfall.
• Moist air rises when it encounters a mountain barrier.
• The rising air cools, condenses and produces rainfall, usually on the windward side.

Last verified on 12-11-2026

Explanation

• The troposphere is the lowest layer of the atmosphere.
• Most weather phenomena occur in this layer.
• Clouds, rain, storms, and winds mainly occur here.
• It extends roughly 8–15 km above Earth’s surface.

• Mesosphere: About 50–85 km; most meteors burn up here.
• Ionosphere: Region with many charged particles; important for radio communication and auroras.
• Stratosphere: About 12–50 km; contains the ozone layer.

Last verified on 12-11-2026

Explanation

• Weathering breaks rocks into smaller pieces at or near the Earth's surface.
• It can occur through physical, chemical and biological processes.
• Unlike erosion, weathering does not involve the transportation of material.

Last verified on 12-11-2026

Explanation

• An ecosystem consists of living organisms (biotic components) and non-living factors (abiotic components).
• Biotic components include plants, animals and microorganisms.
• Abiotic components include air, water, soil, sunlight and temperature.

Last verified on 08-11-2026

Explanation

• Chlorine atoms destroy ozone molecules (O₃) through chemical reactions in the stratosphere.
• Chlorine is mainly released from chlorofluorocarbons (CFCs) when ultraviolet radiation breaks them down.
• One chlorine atom can destroy thousands of ozone molecules before being removed from the stratosphere.
• The Montreal Protocol (1987) was adopted to phase out ozone-depleting substances such as CFCs.

Last verified on 02-11-2026