Chemistry: Matter Around Us Pure

Introduction

• Start of the Discussion: Will be explained based on the chemical properties of matter.
• Pure Substance: Pure is that which has no impurity. Example: Gold, Oxygen, Hydrogen.
• Introduction of the Lecturer: Ananya, Chemistry Teacher

Objective of the Chapter

• One Shot Revision: Revision from the start to the end of the chapter.
• Classification: Matter will be divided into pure and impure substances.

Types of Matter

Pure Substances:

• Classification: Can be classified into elements and compounds.
• Elements: Made of only one type of particle.
  • Example: Gold (gold particles), Oxygen (oxygen particles)
• Compounds: Made of two or more elements.
  • Example: Water (H₂O)

Impure Substances:

• Mixture: Homogeneous and Heterogeneous Mixture
  • Homogeneous: Mixed uniformly, cannot be separated.
  • Heterogeneous: Mixed non-uniformly, can be separated.

Classification of Elements

• Metals: Lustrous, ductile, good conductors (Copper)
• Non-metals: Good insulators (Carbon)
• Metalloids: Properties between metals and non-metals

Characteristics of Matter

• Difference between Pure and Impure: Cannot be separated by chemical reaction.
• Example of Pure Substance: Gold, Water, Oxygen

Solutions, Suspensions, and Colloids

• Solution: Homogeneous mixture; particle size is very small.
• Suspension: Heterogeneous; particles are large and unstable.
• Colloids: Appear homogeneous, but are heterogeneous

Tyndall Effect

• What it is: Scattering of light when it falls on particles.
• Colloids and Suspensions: Show it, but not solutions.

Concentration of Solution

• Mass-by-mass Percentage: Mass of solute/mass of solution × 100

Physical and Chemical Changes

• Physical Change: Nothing new is formed.
  • Example: Melting of ice
• Chemical Change: New things are formed.
  • Example: Burning of wood

Practice Questions

• Strengthening concepts through questions.

Conclusion

• Summary of the Entire Chapter: Strengthen concepts through revision and practice questions.