NCERT 9TH CLASS SCIENCE CHAPTER MATTER IN OUR SURROUNDING
All the substances around us have different shape, size and texture. Everything in universe is made up of matter. The air we breathe, the food we eat, the water we drink, the pen with which we write, the book we read, are made up of matter. In this chapter, we shall discuss the matter in our surroundings.
Important terms and concepts
1. Material :– The term used to describe a particular kind of matter, is called material e.g. – wood,
water and marble.
Type of material :–
2. Matter : It is substance which occupies space and has mass. Air, Earth, Fire, Sky and water five basic element, "The Panch Tatva" according to the earlier Indian Philosophers. According to them everything i.e., living or non-living is made up of these five elements.
3. Classification of Matter : Nowadays scientists have classified matter in the following two ways :
(i) The physical classification based on physical properties of matter and
(ii) The chemical classification based on chemical composition of matter.
4. Physical Nature of Matter : Matter is made up small particles and there is space between particles of matter. It can be proved with the help of following experiment.
Experiment: To show that there is space between particles of matter.
Materials Required : 100 ml beaker, water, salt, glass rod.
Take a 100 ml beaker and fill it with water and mark the level of water.
Dissolve the given salt with the help of glass rod.
Observe the change in the water level and record your observations.
Observations :The salt gets dissolve in water. The particle of salt have entered the space between water molecules, therefore, the level of water does not change.
Conclusion : The salt consists of large number of small particle which occupy the space between molecules of water.
5. Size of Particles of Matter : The particles of matter are extremely small in size which cannot be seen even with powerful microscope. Their size can be observed with the help of following experiment.
Experiment : To show that matter is made up of very small particles.