SCIENCE CLASS IX NCERT

 

Class 9 Science – Chapter 2 Summary Poster

Core Concepts

• Matter exists as elements, compounds, and mixtures.

• Pure substances have fixed composition; mixtures vary.

• Physical changes don’t form new substances; chemical changes do.

Types of Mixtures

Type	Example	Separation Method
Homogeneous	Salt solution	Evaporation
Heterogeneous	Sand + water	Filtration / Decantation

Separation Techniques

• Filtration – separates insoluble solids.

• Evaporation – removes solvent.

• Distillation – separates liquids by boiling point.

• Chromatography – separates colors/pigments.

• Centrifugation – separates based on density.

Formula Box

$$\text{Concentration}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100$$

Exam Tips

• Revise definitions and examples of mixtures & compounds.

• Practice diagrams of separation methods.

• Focus on differences between physical and chemical changes.