NCERT Book Class 9 Science (Exploration) Chapter 13 Earth as a System: Energy, Matter, and Life

Chapter
Earth as a System:

13 Energy, Matter,
and Life

Think It Over Life on Earth is powered by a constant flow of energy and
matter. The Sun is the main source of energy. In addition,
y How does the warming the Earth’s hot interior and chemical reactions in the air,
of Arabian Sea water water, and rocks also drive the flow of energy and matter.
affect the southwest During the middle stage in Curiosity (Grades 6 – 8) and in
monsoon in India? earlier chapters of this textbook, you explored these ideas
y If a large forest is as separate content pieces. For example, you learnt how
cleared, how can that sunlight drives winds and the water cycle; how plants
affect the flow of a river and microbes cycle nutrients; how the Earth’s tilt causes
in that area?
seasons; and how human activities are modifying air,
y What might happen to water, soil and climate. In this chapter, we will consider
coastal cities in India if
these processes together as belonging to one Earth system
glaciers and polar ice
keep melting faster?
made up of interacting ‘spheres’ —
y How would increasing y Geosphere: Solid rocks, soil, landforms (like the Deccan
carbon dioxide levels in plateau and the Thar desert), and the Earth’s interior.
the atmosphere affect y Hydrosphere: Liquid water in the form of surface water,
the ocean plankton? such as oceans, rivers (like the Ganga – Brahmaputra
river system), lakes and groundwater.