Science Class 9
Earth as a System: Energy, Matter, and Life
Sunlight arrives, heats Earth unevenly, and drives the water and carbon cycles.
10 lessons · ~75 min total
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Lessons in this topic
- 0 Start here A roadmap: sunlight in, heat out, uneven heating, the water and carbon cycles, and the five spheres. · 4 min You are here
- 1 One thing arrives Sunlight is the main energy source on Earth, and its energy is intensity times area times time. · 7 min
- 2 What arrives and what leaves The ground sends absorbed sunlight back out as heat, and greenhouse gases hold some of it back. · 9 min
- 3 Not all the same light Sunlight is mostly ultraviolet, visible and infrared light, and each kind does a different job. · 8 min
- 4 Heated unevenly Slant and snow decide how much the ground keeps, and uneven heating drives winds and ocean currents. · 9 min
- 5 Matter goes round Water and other matter go round in cycles between the air, water, land and living things. · 9 min
- 6 Life is in the loop Carbon goes round between air, living things and fuels, on a fast cycle and a slow one. · 9 min
- 7 One system Earth has five spheres, and a change in one sphere can change the others. · 8 min
- 8 The big picture Seven ideas about the Earth as one system: sunlight in, heat out, uneven heating, and the water and carbon that loop. · 4 min
- 9 Track quiz A one-screen cheat sheet, then a question on each idea. · 8 min
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