CBSE · Board years

CBSE Class 9 — Notes, Chapters & Practice Quizzes

Your Class 9 year, organised — chapter notes, board-style questions and a practice quiz for every chapter.

5 subjects 49 chapters 52 practice quizzes NCERT syllabus
90 quiz attempts so far Dual AI-verified questions 10 quizzes free, then ₹9 per quiz
Notice Board

10 questions · instant score · weak-chapter diagnosis

Class 9 students learning
01 Choose a chapter02 Revise key ideas03 Test recall

Students preparing for CBSE Class 9 Annual Assessment

View all
Formula of the day
Maths · Differentiation · 9 formulae in the cheatsheet
Trap of the day
nPr is ordered (arrangements), nCr is unordered (selections). “Arrange” → P, “choose” → C.
IIT JourneyPractice QuizFind weak topicsEnglishHindiMathematicsPhysical EducationScienceMock TestsRehearse exam dayDiscussionAsk the community
Science · 13 chapters
Summary, key terms, extra questions with answers and a practice quiz with AI diagnosis for each.

Chapter 13: Earth as a System: Energy, Matter, and LifeClass 9 Science — summary, notes, extra questions & NCERT solutions

Try one from this chapter
The main source of energy that drives the Earth system is the:

Summary

This concluding chapter brings together ideas from across the book by treating the Earth as a single connected system through which energy and matter constantly flow. The Sun is the main energy source, with extra energy from the Earth’s hot interior and from chemical reactions in air, water and rock. The Earth system is made of interacting ‘spheres’: the geosphere (rocks, soil and landforms such as the Deccan plateau and Thar desert), the hydrosphere (liquid water — oceans, rivers like the Ganga–Brahmaputra, lakes and groundwater), the cryosphere (ice and snow such as Himalayan glaciers and polar caps), the atmosphere (the air we breathe) and the biosphere (all living things). These spheres are linked so that a change in one affects the others. Energy from the Sun drives the winds and the water cycle, while matter is recycled through biogeochemical cycles — the water cycle, the carbon cycle and the nitrogen cycle — that move substances between the living and non-living parts of the planet. The atmosphere’s greenhouse gases trap heat and keep the Earth warm enough for life, but rising carbon dioxide from human activity strengthens this effect and warms the planet, with feedback loops (such as melting ice exposing dark surfaces that absorb more heat) amplifying change. The chapter shows how forest clearing, ocean warming and melting glaciers affect monsoons, rivers, coasts and ocean life, stressing that understanding these connections is essential for protecting the environment and living sustainably.

The Earth as interacting spheresEnergy flow from the Sun and interiorBiogeochemical cycles: water, carbon, nitrogenGreenhouse effect and global warmingFeedback loops and human impact

Key terms

Earth system
The whole planet seen as a set of interacting spheres through which energy and matter flow and influence one another.
Biosphere
The part of the Earth system that contains all living organisms and where they interact with air, water and land.
Biogeochemical cycle
The cyclic movement of a substance (such as water, carbon or nitrogen) between the living and non-living parts of the Earth.
Greenhouse effect
The trapping of heat by certain atmospheric gases that keeps the Earth warm; its strengthening by extra carbon dioxide causes global warming.
Feedback loop
A process in which a change produces effects that further increase (positive) or reduce (negative) that change, as with melting ice exposing dark surfaces.
Spheres of the Earth
The geosphere, hydrosphere, cryosphere, atmosphere and biosphere, which together make up the Earth system.

Extra questions & answers

Think It Over

Activity 13.1: Let us explore

Activity 13.2: Let us find out

Think as a Scientist

Pause and Ponder

Pause and Ponder

Pause and Ponder

Pause and Ponder

Revise, Reflect, Refine

The Journey Beyond

Explore interactively

Key-term flashcards
Flip cards · mark known · keyboard ← → and Space
6 cards
Term1 / 6
Earth system
Tap to reveal
Meaning1 / 6
The whole planet seen as a set of interacting spheres through which energy and matter flow and influence one another.
Tap to flip back
Tap card to flip

Keyboard: ← → to move · Space to flip

Practice quiz · Earth as a System: Energy, Matter, and Life

Score on this chapter, climb the leaderboard, and get an AI diagnosis of your mistakes.

Dual AI-verified questions Real exam pattern 1 free quiz, then ₹9 per quiz — or all at once for up to 30% less

#1

Earth as a System: Energy, Matter, and Life

Start here
Science 10 Qs · ~10 min

Instant score, answer review and weak-topic diagnosis

Your Class 9 board-year rhythm

  1. 1A student studying at home in the evening

    A little every day

    Chapter notes and one quiz a day beat a month of last-minute cramming.

  2. 2Students writing an exam in a bright hall

    Board-pattern practice

    Extra questions with answers and quizzes asked the way the board asks them.

  3. 3A family celebrating a result

    Results you can show off

    Scorecards, leaderboards and AI analysis of every attempt.