Characteristics of Particles of Matter
The important characteristics of particles of matter are the following:
- The particles of matter are very, very small.
- The particles of matter have space between them.
- The particles of matter are constantly moving.
- The particles of matter attract each other.
1. The particles of matter are very, very small:
The very, very small size of particles of matter can not be seen by naked eyes.
2. The particles of matter have space between them:
The spaces between the particles of matter can be shown by performing the following experiment by using water and sugar.
- Take a 100 ml beaker.
- Fill half the beaker with water and mark the level of water.
- Dissolve some sugar (50gm) with the help of a glass rod.
- We will find that the level of sugar solution in the beaker is at the same mark where water level was initially in the beaker.
- When sugar is dissolved in water, its crystals separate into very fine particles. These particles of sugar go into the spaces between the various particles of water due to which there is no change in the volume of water on dissolving sugar in it.
- The fact that there is no change in volume on dissolving sugar in water tells us that there are spaces between the particles of water.
3. The particles of Matter are constantly moving:
The best evidence that particles of matter are constantly moving comes from the experiments on diffusion and Brownian motion.
If we notice the smoke coming out from any fragrance stick (Agarbatti) or cigarette ; what happen to smoke as it comes out. It spread into atmosphere. Why it spread into atmosphere ; why not collected into small volume. The Gas particles keep on moving constantly and this random movement result into their intermixing.
Solid and Liquid particles also move continuously .
| Solid Particles movement is fixed at their mean position and continuously vibrations are present. As the temperature increases their particles vibrations speed increases and beyond a certain high temperature the kinetic energy of solid particles become too high that they melt into liquid. |
4. The particles of Matter attract each other:
- There are some forces of attraction between the particles of matter which bind them together.
- The force of attraction between the particles of the same substance is known as Cohesive Force .
- If we take a piece of chalk, a cube of ice and an iron nail, and beat them with a hammer, we will find that it is very easy to break the piece of chalk into smaller particles, it requires more force to break a cube of ice, whereas the iron nail does not break at all even with a large force.
- This shows that the force of attraction between the particles of chalk is quite weak; the force of attraction between the particles of ice is a bit stronger whereas the force of attraction between the particles of iron nail is very, very strong.
- Note: In general, the force of attraction is maximum in the particles of solids matter and minimum in the particles of a gaseous matter.
- Note: rigid means ‘unbending’ or ‘inflexible’. A stone is rigid because it is unbending or inflexible.
Fluid means a material which can flow easily and requires a vessel to keep it.
