this chapter is very lengthy ?can you plz send me some short notes which has every imp topic.

First of all you have not specified which chapter you are having doubts in. Secondly it is not possible to send notes on whole chapter. Go through the chapterand wherever you are having doubts, post questions on each doubt separately. Then I will be able to answer them and clear all your doubts. You are feeling that the chapter is lengthy since you are trying to read it all at once. Try to cover only one or 2 pages in a day. Clear the doubts that you have in those topics. Proceed further only after you have totally understood those pages. Then you will feel that the chapter is quite easy.