Particles of Matter PDF

Particles of matter are continuously moving, that is, they possess what we call the kinetic energy. As the temperature rises, particles move faster. So, we can say that with increase in temperature the kinetic energy of the particles also increases. In the above three activities we observe that part...

Particles of matter are continuously moving, that is, they possess what we call the kinetic energy. As the temperature rises, particles move faster. So, we can say that with increase in temperature the kinetic energy of the particles also increases. In the above three activities we observe that particles of matter intermix on their own with each other. They do so by getting into the spaces between the particles. This intermixing of particles of two different types of matter on their own is called diffusion. We also observe that on heating, diffusion becomes faster. Why does this happen? 1.2.3 PARTICLES Activity ______________ 1.7 Activity ______________ 1.6 Play this game in the field— make four groups and form human chains as suggested: The first group should hold each other from the back and lock arms like Idu-Mishmi dancers (Fig. 1.3). M AT T E R The second group should hold hands to form a human chain. The third group should form a chain by touching each other with only their finger tips. Now, the fourth group of students should run around and try to break the three human chains one by one into as many small groups as possible. Which group was the easiest to break? Why? IN Take some water in a container, try cutting the surface of water with your fingers. Were you able to cut the surface of water? What could be the reason behind the surface of water remaining together? The above three activities (1.6, 1.7 and 1.8) suggest that particles of matter have force acting between them. This force keeps the particles together. The strength of this force of attraction varies from one kind of matter to another. Q Fig. 1.3 Take an iron nail, a piece of chalk and a rubber band. Try breaking them by hammering, cutting or stretching. In which of the above three substances do you think the particles are held together with greater force? Activity ______________ 1.8 OF MATTER ATTRACT EACH OTHER If we consider each student as a particle of matter, then in which group the particles held each other with the maximum force? uestions 1. Which of the following are matter? Chair, air, love, smell, hate, almonds, thought, cold, lemon water, smell of perfume. 2. Give reasons for the following observation: The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close. 3. A diver is able to cut through water in a swimming pool. Which property of matter does this observation show? 4. What are the characteristics of the particles of matter? 3 O U R S U R R O U N D I N GS Rationalised 2023-24