Matter In Our Surroundings

Matter In Our Surroundings
Part I

·         Anything that occupies space and has mass is called matter.
·         It exists in the form of five basic elements, the “Panch Tatva” – air, earth, fire, sky and 
       water. ( According to Early Indian philosophers)
·         For example: Chair, bed, river, mountain, dog, tree, building etc.
·         Modern day scientists have evolved two types of classification of matter based on their 
       physical properties and chemical nature.

Physical nature of matter

       1.       Matter is made up of particles

        i.            Take a 100 mL beaker.
      ii.            Fill half the beaker with water and mark the level of water.
    iii.            Dissolve some salt with the help of a glass rod.

Observation: We observe that when salt is dissolved in water there is no rise in the level of water.
Conclusion: During dissolution, the particles of salt get into the spaces between the particles of water. As a result, they get evenly distributed and there is no change in volume.

       2.       Particles of matter are very small
                    i.            Take 2-3 crystals of potassium permanganate and dissolve them in 100 mL of water.
                  ii.            Take out approximately 10 mL of this solution and put it into 90 mL of water.
                iii.            Repeat this step for 5 to 8 times.
Observation: We will see that the colour of the solution turns lighter on each dilution. This activity shows that just a few crystals of potassium permanganate can colour a large volume of water.
Conclusion: This activity proves that matter is made up of tiny particles. So we conclude that there must be millions of tiny particles in just one crystal of potassium permanganate, which keep on dividing themselves into smaller and smaller particles. Ultimately a stage is reached when the particles cannot divide further into smaller particles.

Characteristics of particles of matter
       1.        Particles of matter have space between them.
       2.        Particles of matter are continuously moving.
                                i.            Particles of matter possess kinetic energy.
                              ii.            As the temperature increases particles move faster.
                            iii.            Increase in temperature increases the kinetic energy.
                            iv.            Due to this reason smell of incense stick spreads through out, blue or red ink 
                           spreads through out the glass of water and crystals of copper sulphate gets mixed at  
                           faster rate in hot water.
                          v.             In activities 1.3,1.4, 1.5 we observe that particles of matter intermix on their own. 
                         This happens due to the spaces between the particles.
                       vi.        Intermixing of particles of two different types of matter on their own is called diffusion.
                      vii.       Increase in temperature increases rate of diffusion.
      3.        Particles of matter attract each other.
                         i.         Attraction between the particles is due to forces of attraction acting upon them. So we can conclude that out of iron nail, a piece of chalk and a rubber band, particles of iron nail are held together with greater force.

                                                                                     Prepared by Ms. Priti Maan

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