Science Exploration Notes Class 9 English Medium 2026-27

Science Exploration Chapter 13. Earth as a System: Energy, Matter, and Life

CBSE Notes New Syllabus: Class 9

Assignments - What Have You Learned?

Chapter 13. Earth as a System: Energy, Matter, and Life

This assignment is designed to help students revise the concepts of Earth's interconnected systems, solar energy, atmosphere, winds, ocean currents and biogeochemical cycles. Attempt all questions carefully to strengthen conceptual understanding and prepare for school examinations. 

Assignment – What Have You Learned?

A. Fill in the Blanks

1. The __________ is the primary source of energy for the Earth.
2. The solid part of the Earth is called the __________.
3. The fraction of solar radiation reflected by a surface is known as __________.
4. The layer of the atmosphere that contains the ozone layer is the __________.
5. Wind always blows from __________ pressure to __________ pressure.
6. The movement of seawater in a particular direction is called an __________.
7. The process by which plants release water vapour is called __________.
8. Plants absorb __________ during photosynthesis.
9. The continuous recycling of nutrients between living and non-living components is called the __________ cycle.
10. The international agreement that protects the ozone layer is the __________.

B. State True or False

1. The biosphere includes all living organisms.
2. Dark-coloured surfaces have higher albedo than snow.
3. Infrared radiation mainly heats the Earth's surface.
4. The greenhouse effect is completely harmful for life.
5. Sea breeze blows from the sea towards the land during the daytime.
6. Ocean currents help regulate the Earth's climate.
7. Carbon is present in proteins, carbohydrates and DNA.
8. Groundwater is recharged through infiltration.
9. Planetary winds are caused by large-scale pressure differences.
10. The water cycle connects all the Earth's spheres.

C. Answer in One Sentence

1. What is the Earth System?
2. Define solar radiation.
3. What is insolation?
4. What is the solar constant?
5. Define albedo.
6. Why is the ozone layer important?
7. What are greenhouse gases?
8. What is a valley breeze?
9. Define ocean currents.
10. What is a biogeochemical cycle?

D. Short Answer Questions

1. Explain the five major spheres of the Earth.
2. Differentiate between reflection and absorption of solar radiation.
3. Why do equatorial regions receive more solar energy than polar regions?
4. Explain the greenhouse effect.
5. Describe the formation of sea breeze and land breeze.
6. State the importance of ocean currents.
7. Explain the major stages of the water cycle.
8. Describe the fast carbon cycle.

E. Long Answer Questions

1. Explain how energy flows through the Earth System and why it is essential for life.
2. Describe the structure of the atmosphere and explain the importance of each layer.
3. Explain how uneven heating of the Earth causes winds and ocean currents.
4. Describe the water cycle and explain how climate change affects it.
5. Explain the carbon cycle and discuss how human activities disturb its balance.

F. Higher-Order Thinking Skills (HOTS)

1. Why do snow-covered mountains remain cooler than black roads even under the same sunlight?
2. How would the Earth's climate change if greenhouse gases were completely absent?
3. Explain how melting glaciers affect the hydrosphere, biosphere and human life.
4. How does deforestation disturb both the water cycle and the carbon cycle?
5. Why are ocean currents important for coastal climate and marine life?

G. Activity-Based Questions

1. Observe different coloured surfaces around your home and identify which absorb more heat.
2. Draw and label the five Earth spheres.
3. Prepare a labelled flowchart of the water cycle.
4. Draw the carbon cycle showing photosynthesis, respiration and decomposition.
5. Collect newspaper reports on climate change and identify the Earth spheres affected.

ATP Education Practice Tip

Revise the definitions of important terms such as Earth System, albedo, insolation, greenhouse effect, ozone layer, ocean currents, water cycle and carbon cycle. Practice labelled diagrams of the Earth's spheres, atmosphere, water cycle and carbon cycle, as these are frequently asked in CBSE examinations.