CBSE Class 9 Science Revision Notes
Chapter wise Revision Notes for Class 9 Science
Q 1: How many chapters are there in CBSE Class 9 Science?
Ans: There are a total of 15 chapters in class 9 science. The first half of the syllabus comprises of chapter 1: matters in our surroundings, chapter 2: Is matter around us pure, chapter 3: atoms and molecules, chapter 4: structure of the atoms, chapter 5: the fundamental unit of life, chapter 6: tissues and chapter 7: diversity in living organisms.
The second part of the syllabus consists of chapter 8: motion, chapter 9: force and laws of motion, chapter 10: gravitation, chapter 11: work and energy, chapter 12: sound, chapter 13: why do we fall ill, chapter 14: natural resources and chapter 15: improvements in food resources.
Q 2: What is the propagation of sound?
Ans: Here, you will get to know how vibration in objects produces sound. On carrying off the activities, you will be gaining a basic idea of sound vibrations. In this section, you will find the theoretical explanation of sound energy, its creation and propagation. You shall also come across how the particles in a medium vibrate to propagate a sound wave through it. In fact, it shall also show that the particles resume their equilibrium once the sound waves pass through it.
On proceeding further, sound waves produce compressions and rarefactions in a medium. These phenomena shall happen only when the sound energy disturbs the particles in a medium with the help of a diagram. On elaborating about the compression and rarefaction, you will understand by experiments that sound energy needs a medium to propagate.
Q 3: Brief about the chapter Natural Resources.
Ans: This chapter discusses why natural resources are required for life and how life is supported on the planet earth. Here, you will know a glimpse of the factors needed for life, like water, food, optimal ambient temperature, and energy from the sum. The lithosphere and hydrosphere are defined and the biosphere is explained. Components of the biosphere are discussed. Then, the chapter teaches you about the abiotic components on the earth’s crust to make you understand their roles in supporting life on earth. The chapter mainly focuses on:
The breath of life: air
The role of the atmosphere in climate control
The movements of air: winds
Water: a wonder liquid
Mineral riches in the soil
The water cycle
The nitrogen cycle
The carbon cycle
The oxygen cycle
Q 4: Will Vedantu helps me with the exam preparation?
Ans: At Vedantu, we aim towards simplifying the process of learning for students. That is why our solutions for NCERT books are provided in PDF format for you to download it freely without the hassle of a lengthy registration process. Further, we also provide one on one online classes with our expert teachers, who can provide students with a much more in-depth knowledge of respective subjects. The questions cover all the important topics and subtopics of the chapter which could be expected in your Class 9 science exams. Therefore, if you are looking for a way to streamline your exam preparations, check the solutions PDF on our official website.