Class 9 Science Chapter 1 Matter In Our Surrounding Study Notes

Matter
The matter is the material of which everything in this universe, in and around us is made up of in different shapes. It is anything that occupies space and has mass and offers resistance to any applied force.
Physical Nature of Particles :
Matter is made up of particles. The particles of matter are very-very small.

Characteristics of Particles :
(i) Particles of matter are continuously moving i.e., they possess kinetic energy. As the temperature rises, particles moves faster because kinetic energy of the particles increases.
(ii) Particles of matter have space between them. When we make tea, coffee or lemonade (nimbu pani), particles of one type of matter get into the space between particles of the other. This shows that there is enough space between particles of matter.
(iii) Particles of matter attract each other. When we open a water tap, try to break the stream of water with your fingers, can we do this ? No, because the stream of water remains together. Particles
of water are held together because of the force of attraction between them.

• The space between the particles and kinetic energy of particles is minimum in solids, intermediate in liquids and maximum in gases.

• The force of attraction between the particles is strongest in solids, intermediate in liquids and weakest in gases.

• Movement of particles is minimum in solids, more in liquids and maximum in gases.