NCERT Class 9 Social Science Understanding Society India and Beyond PART-I: Chapter 3 — Atmosphere and Climate
This chapter, "Atmosphere and Climate," from NCERT Class 9 Social Science's "Understanding Society: India and Beyond PART-I," explores the Earth's atmosphere. It begins by defining the atmosphere as a vital blanket of air surrounding Earth, held by gravity, and composed of various gases, water vapour, and dust particles. The chapter highlights the atmosphere's crucial role in shielding us from harmful solar radiation and regulating Earth's temperature. It then delves into the composition, detailing nitrogen (78%) and oxygen (21%) as the primary gases, along with smaller amounts of carbon dioxide, argon, and others. The structure of the atmosphere, based on temperature and density changes with altitude, is also introduced. Understanding these elements is fundamental for grasping Earth's weather and climate systems, essential for CBSE learning.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 9 |
| Subject | Social Science |
| Book | Understanding Society India and Beyond PART-I |
| Chapter | Chapter 3 — Atmosphere and Climate |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 482 |
Learning outcomes
- Understand the composition of the Earth's atmosphere.
- Recognize the importance of the atmosphere for life on Earth.
- Identify the main gases present in the atmosphere.
- Understand the basic structure of the atmosphere.
- Appreciate the role of the atmosphere in regulating Earth's temperature and shielding from radiation.
Vocabulary
| Word | Meaning |
|---|---|
| Atmosphere | A blanket of air surrounding the Earth. |
| Gravity | A fundamental physical force of attraction between objects with mass or energy. |
| Nitrogen | The most abundant gas in Earth's atmosphere (78%). |
| Oxygen | The second most abundant gas in Earth's atmosphere (21%), essential for life. |
| Carbon Dioxide | A gas present in the atmosphere in lesser quantities, important for climate. |
| Water vapour | Water in gaseous form present in the atmosphere, crucial for cloud formation and precipitation. |
| Dust particles | Tiny solid particles suspended in the atmosphere. |
| Altitude | The height of an object or point in relation to sea level or ground level. |
| Density | The degree of compactness of a substance, measured as mass per unit volume. |
| Radiation | Energy transmitted through space or a medium. |
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Practice questions
- What is the atmosphere? Answer: The atmosphere is a blanket of air surrounding the Earth, composed of a mixture of gases, water vapour, and dust particles.
- Name the two most abundant gases in the Earth's atmosphere. Answer: Nitrogen (78%) and Oxygen (21%) are the two most abundant gases.
- What is the role of the atmosphere in protecting life on Earth? Answer: The atmosphere shields us from harmful solar radiation and regulates Earth's temperature.
- What factors define the layered structure of the atmosphere? Answer: The layered structure is defined by changes in temperature and density with increasing altitude.
Frequently asked questions
What is the atmosphere?
The atmosphere is the layer of gases surrounding the Earth, held in place by gravity, which is vital for life.
What are the main gases in the atmosphere?
The main gases are Nitrogen (78%) and Oxygen (21%), with smaller amounts of Carbon Dioxide, Argon, and others.
How does the atmosphere protect Earth?
It shields Earth from harmful solar radiation and helps regulate its temperature.
What is gravity's role concerning the atmosphere?
Gravity pulls the atmosphere down around the Earth, keeping it from escaping into space.
What is the composition of the atmosphere besides gases?
The atmosphere also contains water vapour and tiny dust particles.
How is the atmosphere structured?
The atmosphere has a layered structure based on changes in temperature and density with altitude.
Related resources
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Topics covered
NCERT Class 9 Social Science — Understanding Society India and Beyond PART-I — Chapter 3 — Atmosphere and Climate. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.