In this post, we learn about the chapter Notes of Some Natural Phenomena of CBSE Class 8 Chapter 15 pointwise and cover all the important points.
Some Natural Phenomena CBSE Notes
1. Some objects can be charged by rubbing with other objects.
2. There are two kinds of charges — positive charge and negative charge
3. Like charges repel and unlike charges attract each other.
4. The electrical charges produced by rubbing are called static charges.
5. When charges move, they constitute an electric current.
6. An electroscope may be used to detect whether a body is charged or not.
7. The process of transfer of charge from a charged object to the earth is called earthing.
8. The process of an electric discharge between clouds and the earth or between different clouds causes lightning.
9. Lightning strikes could destroy life and property.
10. Lightning conductors can protect buildings from the effects of lightning.
11. An earthquake is a sudden shaking or trembling of the earth.
12. Earthquake is caused by a disturbance deep inside the earth’s crust.
13. It is not possible to predict the occurrence of an earthquake.
14. Earthquakes tend to occur at the boundaries of the earth’s plates. These boundaries are known as fault zones.
15. Destructive energy of an earthquake is measured on the Richter scale. The earthquake measuring 7 or more on the Richter scale can cause severe damage to life and property.
16. We should take necessary precautions to protect ourselves from earthquakes.
17. Richter Scale: A logarithmic scale, ranging from 1 to 10 for indicating the intensity of an earthquake.
18. Seismic Waves: The energy released at the focus of an earthquake, propagates outwardly.
19. Seismograph: An instrument by which seismic waves of an earthquake are monitored.
20. Epicentre: A point on the earth above the seismic force.
21. Fault Zones: Earthquake-prone areas in the earth’s crust.