Class 9 revision Notes

 Matter

There are three types of matter:

1. Solid
2. Liquid
3. Gas

It is something that has volume and occupies mass.

Inter-particle spaces

The spaces between particles of matter are known as inter-particle spaces.
Gases have more spaces between their particles as compared to solids and liquids.

Gases, liquids, and solids

There are no interparticle interactions in solids because the particles of solids are tightly packed.
Diffusion: The mixing of particles of two different types of matter is known as diffusion. For example, water and salt; milk and sugar; oil and water; etc.

The particles of solids are tightly packed, and the particles of gases are loosely packed Since then, we have heated the object. Its kinetic energy increases as the object's velocity increases.
The particles of substances keep moving. They collide with each other as well as with the walls of the container.

1. They always move in Brownian motion.
2. They have interparticle spaces.

The particles of solids are tightly packed. So the force of attraction is at its maximum.
The particles of gases are loosely packed. So the force of attraction is minimal.

Matter transformation

1. Temperature
2. Pressure

Temperature

• Fusion is the transformation of a solid into a liquid.
• The process of converting liquid to solid is known as freezing.
• Evaporation is the conversion of a liquid to a gas.
• Condensation is the transformation of a gas into a liquid.
• Sublimation is the transformation of a gas into a solid.
• Sublimation is the transformation of a solid into a gas.

Fusion: the process by which solids get converted into liquids For instance, ice to water, metal to liquid, and so on.

Boiling point: The boiling point is the temperature at which a liquid starts to vaporise into a gas Sublimation is the process by which solids get converted directly into a gas without passing through a liquid phase Fusion and boiling point are related processes in the sense that both involve changing a substance's state from one form to another. Fusion is the process of changing a solid directly into a liquid, whereas boiling point is when a liquid changes into a gas and the temperature at which liquids get converted into vapours at atmospheric pressure.

The amount of material required to convert 1 kg of solid into liquid at its boiling point is known as the latent of fusion.

At atmospheric pressure, the melting point is the temperature at which solids become liquids. 

Class 9 Science Syllabus for CBSE Board | ChemistryABC.com