0It is an elementary and exciting chapter in class 9. You can note this lesson as your revision notes as well.
You see several things in this universe, what do you think this universe is made up of? It is made up of matter.
ALL ABOUT MATTER AND ITS NATURE
- The matter is anything and everything that occupies space and has mass. It also offers resistance, that is why we need to apply some kind of force while doing any particular task.
- Matter can be felt by our five senses, ignoring/eliminating all the emotions because that neither occupies any space nor has any mass.
- Some examples are mountains, table, milk, the smell of perfume etc.
NOTE: vacuum is not considered to be a matter because there are no particles; hence nothing is occupying space and mass.
Coming on to the characteristics/properties of matter or nature/behaviour of matter:
1) The matter is particulate, i.e., and it is made up of small particles called atoms.
2) The particles of matter are so small that our eyes cannot observe them.
3) The particles of matter are continuously moving.
4) The particles of matter have space between them known as intermolecular space
5) The particles of matter are attracted to each other by the force of attraction, also known as the intermolecular force of attraction.
EXPERIMENTS
All the characteristics and properties can be observed through some easy and straightforward experiments:
Experiment 1: You must have observed that whenever salt is dissolved in water, the level of water does not rise. Have you ever wondered why? Because the particles of water have space between them, which when salt is added, is taken by the particles of salt resulting in no rise in the level of water.
By this experiment, you can conclude that particles of matter have space between them and also the particles of matter are constantly/continuously moving.
Experiment 2: Now comes the concept of DIFFUSION. It is the process of intermixing of particles into each other. Giving some examples through small experiments and observations, Take crystals of potassium permanganate (purple). When you try to mix or dissolve it in water the force if the attraction of the particles of crystals weakens which leads to the particle diffusion and then the particles of crystals dissolves in the water after which the water solution looks purple.
Another example can be an incense stick(Agarbatti). The smell of lit incense stick diffuses into the whole room, why? Because the particles of incense stick intermix with the particles present in the air. Also, diffusion becomes faster and accessible when the temperature increases; that is why unlit incense sticks cannot be smell even when it is near you.
Now can you answer, How does the smell of food being cooked in the kitchen reach us even from a considerable distance?
I hope this lesson was useful, to continue to learn about this chapter do read part 2
