Geography · Class 11 Arts
Ch 13Composition and Structure of Atmosphere — Class 11 Geography, concept-first.
The atmosphere is not some distant, abstract layer — it is the very envelope of air we live inside, and we depend on it every few seconds. That dependence is the starting point for studying what the atmosphere is made of and how it is arranged.
Key concepts
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Ozone Layer Depletion
Think of the ozone layer as a very thin, invisible sunscreen wrapped around the Earth, floating roughly 15 to 35 kilometres above your head.
Most relevant Q&A
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
Introduction
The atmosphere is not some distant, abstract layer — it is the very envelope of air we live inside, and we depend on it every few seconds.
Composition of the Atmosphere
The atmosphere is not a single, uniform gas but a layered mixture of three broad components: gases, water vapour, and dust particles.
Gases
The atmosphere is a mixture of gases, but not all gases play an equal role in the earth’s weather and climate. Two gases stand out for their special functions: carbon dioxide and ozone.
Water Vapour
Water vapour is the most variable of the atmosphere’s gases, and its amount changes sharply with place, altitude, and temperature.
Dust Particles
The atmosphere is not just a mixture of gases — it also holds a vast number of tiny solid particles suspended within it.
Structure of the Atmosphere
The atmosphere is not a uniform blanket of air. It is built as a series of layers, each with its own character, and the two properties that change most noticeably as you go up are density and temperat…
Elements of Weather and Climate
The atmosphere is not a static blanket around the Earth. It is a dynamic system whose various components are constantly changing, and these changes directly shape the conditions we experience as weath…
More questions
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- Q1Which one of the following gases constitutes the major portion of the atmosphere? (a) Oxygen (b) Nitrogen (c) Argon (d) Carbon dioxideFree
- Q2Atmospheric layer important for human beings is: (a) Stratosphere (b) Mesosphere (c) Troposphere (d) IonosphereFree
- Q3Sea salt, pollen, ash, smoke soot, fine soil -- these are associated with: (a) Gases (b) Dust particles (c) Water vapour (d) MeteorsPreview
- Q4Oxygen gas is in negligible quantity at the height of atmosphere: (a) 90 km (b) 120 km (c) 100 km (d) 150 kmPreview
- Q5Which one of the following gases is transparent to incoming solar radiation and opaque to outgoing terrestrial radiation? (a) Oxygen (b) Nit…Preview