Lesson-1 Matter in Our Surroundings
Matter
- All things which we see around us and use in our everyday life together constitute matter.
- Anything which occupies space and has mass is called matter.
- Matter is made up of particles.
Types of Matter
There are two ways in which matter can be classified-
1. On the basis of its physical nature (physical state).
2. On the basis of its chemical constitution.
Characteristics of Particles of Matter
The particles of matter—
- are very small.
- have spaces between them
- are continuously moving.
-attract each other.
Diffusion
- Intermixing of particles of two different types of matter on their own is called diffusion.
- The rate of diffusion increases on increasing the temperature of the diffusing substance (by
heating).
Examples of diffusion in gases:
-The aroma of food being cooked in the kitchen reaches us even from a considerable distance due to
diffusion.
-The fragrance of a burning incense stick spreads all around due to diffusion.
-The fragrance of a perfume spreads due to the diffusion of the perfume particles into air.
Examples of diffusion in liquids:
-Colour of potassium permanganate is acquired by water, on its own, due to the diffusion of
potassium permanganate particles in water.
- The spreading of ink in water, on its own, is due to the diffusion of ink particles in the water.
Examples of diffusion in solids:
- If two metal blocks are bound together tightly and kept undisturbed for a few years, then the
particles of one metal are found to have diffused into the other metal.
, - If we write something on a blackboard and leave it undisturbed for at least 10 to 15 days, we will
find that it becomes quite difficult to clean the blackboard afterwards. This is due to the fact that
some of the particles of chalk have diffused into the surface of the blackboard.
Matter
- All things which we see around us and use in our everyday life together constitute matter.
- Anything which occupies space and has mass is called matter.
- Matter is made up of particles.
Types of Matter
There are two ways in which matter can be classified-
1. On the basis of its physical nature (physical state).
2. On the basis of its chemical constitution.
Characteristics of Particles of Matter
The particles of matter—
- are very small.
- have spaces between them
- are continuously moving.
-attract each other.
Diffusion
- Intermixing of particles of two different types of matter on their own is called diffusion.
- The rate of diffusion increases on increasing the temperature of the diffusing substance (by
heating).
Examples of diffusion in gases:
-The aroma of food being cooked in the kitchen reaches us even from a considerable distance due to
diffusion.
-The fragrance of a burning incense stick spreads all around due to diffusion.
-The fragrance of a perfume spreads due to the diffusion of the perfume particles into air.
Examples of diffusion in liquids:
-Colour of potassium permanganate is acquired by water, on its own, due to the diffusion of
potassium permanganate particles in water.
- The spreading of ink in water, on its own, is due to the diffusion of ink particles in the water.
Examples of diffusion in solids:
- If two metal blocks are bound together tightly and kept undisturbed for a few years, then the
particles of one metal are found to have diffused into the other metal.
, - If we write something on a blackboard and leave it undisturbed for at least 10 to 15 days, we will
find that it becomes quite difficult to clean the blackboard afterwards. This is due to the fact that
some of the particles of chalk have diffused into the surface of the blackboard.
