Class 9 Science Chapter 1: Matter in Our
Surroundings - Handwritten Notes by MD Sir
1.1 Physical Nature of Matter
Matter is Made Up of Particles
• Matter bohot chhote particles se bana hota hai jo water mein
namak/cheeni ghulane se pata chalta hai.
• Example: Chai banate waqt cheeni paani mein ghul jaati hai.
How Small Are These Particles?
• Potassium permanganate ko dilute karte rehne par bhi rang dikhai deta
hai, jo particles ki chhoti size ko dikhata hai.
Characteristics of Particles of Matter
1. Particles Have Space Between Them
o Example: Cheeni paani mein ghul jaati hai, jo space ko dikhata
hai.
2. Particles are Continuously Moving
o Example: Agarbatti ki khushboo kamre mein fail jaati hai.
3. Particles Attract Each Other
o Example: Diver paani ko cut kar sakta hai par wood ko nahi, jo
attraction level ko dikhata hai.
1.2 States of Matter
Solid State
• Characteristics: Fixed shape, boundaries, volume, aur rigid.
• Example: Pen, book, needle.
• Special Case: Rubber band force hatane par wapas aa jaata hai.
Liquid State
• Characteristics: Fixed volume, no fixed shape, aur fluid.
• Example: Paani, doodh, juice.
, Gaseous State
• Characteristics: No fixed shape, volume, aur highly compressible.
• Example: Gas balloon, LPG, CNG.
1.3 Can Matter Change Its State?
Effect of Temperature
• Melting Point: Solid to liquid conversion temperature.
o Example: Baraf 0°C par melt hota hai.
• Boiling Point: Liquid to gas conversion temperature.
o Example: Paani 100°C par boil hota hai.
• Latent Heat: State change ke liye required heat.
o Fusion: Solid to liquid.
o Vaporization: Liquid to gas.
Effect of Pressure
• Increasing Pressure: Gases ko liquefy kar sakte hain.
o Example: Dry ice (solid CO2) directly gas banta hai.
Sublimation
• Definition: Solid se directly gas banana.
o Example: Kapoor (camphor) sublimate hota hai.
1.4 Evaporation
Definition
• Evaporation: Liquid ka vapor mein change below boiling point.
Factors Affecting Evaporation
1. Surface Area: Jyada area se evaporation increase hota hai.
o Example: Kapde spread karne par jaldi dry hote hain.
2. Temperature: Higher temperature se evaporation increase hota hai.
3. Humidity: Lower humidity se evaporation increase hota hai.
4. Wind Speed: Higher wind speed se evaporation increase hota hai.
Surroundings - Handwritten Notes by MD Sir
1.1 Physical Nature of Matter
Matter is Made Up of Particles
• Matter bohot chhote particles se bana hota hai jo water mein
namak/cheeni ghulane se pata chalta hai.
• Example: Chai banate waqt cheeni paani mein ghul jaati hai.
How Small Are These Particles?
• Potassium permanganate ko dilute karte rehne par bhi rang dikhai deta
hai, jo particles ki chhoti size ko dikhata hai.
Characteristics of Particles of Matter
1. Particles Have Space Between Them
o Example: Cheeni paani mein ghul jaati hai, jo space ko dikhata
hai.
2. Particles are Continuously Moving
o Example: Agarbatti ki khushboo kamre mein fail jaati hai.
3. Particles Attract Each Other
o Example: Diver paani ko cut kar sakta hai par wood ko nahi, jo
attraction level ko dikhata hai.
1.2 States of Matter
Solid State
• Characteristics: Fixed shape, boundaries, volume, aur rigid.
• Example: Pen, book, needle.
• Special Case: Rubber band force hatane par wapas aa jaata hai.
Liquid State
• Characteristics: Fixed volume, no fixed shape, aur fluid.
• Example: Paani, doodh, juice.
, Gaseous State
• Characteristics: No fixed shape, volume, aur highly compressible.
• Example: Gas balloon, LPG, CNG.
1.3 Can Matter Change Its State?
Effect of Temperature
• Melting Point: Solid to liquid conversion temperature.
o Example: Baraf 0°C par melt hota hai.
• Boiling Point: Liquid to gas conversion temperature.
o Example: Paani 100°C par boil hota hai.
• Latent Heat: State change ke liye required heat.
o Fusion: Solid to liquid.
o Vaporization: Liquid to gas.
Effect of Pressure
• Increasing Pressure: Gases ko liquefy kar sakte hain.
o Example: Dry ice (solid CO2) directly gas banta hai.
Sublimation
• Definition: Solid se directly gas banana.
o Example: Kapoor (camphor) sublimate hota hai.
1.4 Evaporation
Definition
• Evaporation: Liquid ka vapor mein change below boiling point.
Factors Affecting Evaporation
1. Surface Area: Jyada area se evaporation increase hota hai.
o Example: Kapde spread karne par jaldi dry hote hain.
2. Temperature: Higher temperature se evaporation increase hota hai.
3. Humidity: Lower humidity se evaporation increase hota hai.
4. Wind Speed: Higher wind speed se evaporation increase hota hai.
