Please give me notes on science class 8 chapter 2

Dear Student,
 
Kindly refer to the link provided below to the asked query:
https://www.meritnation.com/cbse/class8/studymaterial/science/science/1_8_2_6
 
Hope this information will clear your doubts about the topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
 
Regards