Chapter 1: Matter in our surroundings

• Matter


  Anything that occupies space and has mass
• Panch Tatva


  Early Indian Philosophers classified matter in the form of five basic elements— the ‘Panch Tatva’- air, earth, fire, sky and water. Everything living or non living was made up of these.
• Physical Nature of Matter:

  • Matter is made up of particles
  • Particles are very tiny in size
• Characteristics of Particles of Matter

  • Have space between them
  • Continuously moving
  • Attracts each other
• States of Matter

  • Solid
  • Liquid
  • Gas
• The Solid State

  • Definite shape
  • Fixed Volume
  • Fixed Mass
  • Particles tightly packed
  • Space between particles minimum
  • Movement of particles minimum
  • Force Of Attraction maximum
  • Least compressible
  • Rate of diffusion is minimum
  • Rigid
• The Liquid State

  • No definite shape
  • fixed volume
  • fixed mass
  • particles loosely packed
  • space between particles intermediate
  • movement of particles intermediate
  • force of attraction intermediate
  • Less compressible
  • rate of diffusion is intermediate
  • fluids
• The Solid State

  • No definite shape
  • No fixed volume
  • No fixed mass
  • Particles very loosely packed
  • Space between particles maximum
  • Movement of particles maximum
  • Force of attraction minimum
  • Easily compressible
  • Rate of diffusion is maximum
  • Fluid
• Can Matter Change it’s State?

  Yes

  • By Temperature
  • By Pressure
• Fusion


  Solid To liquid by Heating
• Solidification


  Liquid to Solid by Cooling
• Vaporization


  Liquid to Gas by Heating
• Condensation


  Gas to Liquid by Cooling
• Sublimation


  Solid to Gas by Heating

  • Naphthalene
  • Dry Ice
• Deposition


  Gas to Solid by Cooling

  • Camphor
  • Iodine
  • Ammonium Chloride
• Melting Point


  Temperature at which solid melts to liquid at atmospheric pressure.

  Ice- 0°C = 273K
• Boiling Point


  Temperature at which liquid boils at atmospheric pressure. This is a Bulk phenomenon

  Water- 100°C = 373 K
• Latent Heat of Fusion


  Amount of Heat energy required to change 1kg of solid to liquid at atmospheric pressure at its melting point.
• Later Heat of Vaporisation


  Amount of heat energy required to change 1 kg liquid to gas at atmospheric pressure at boiling point.
• By Pressure

  Applying Pressure- Particles of matter gets closer

  Ex: Dry ice stored under high pressure.
• Evaporation


  The surface phenomenon of change of a liquid into vapors at any temperature below boiling point.
• What happens in Evaporation?

  Particles near the surface gain kinetic energy from the surroundings and overcomes the force of attraction to evaporate away due to this high kinetic energy.
• Rate of Evaporation depends on:

  • Surface Area
  • Temperature
  • Humidity
  • Wind speed
• Cooling effect


  Particles on surface gain energy from surroundings or surface and evaporate causing coolness.
• Examples of Cooling Effect:

  • Cotton is a good absorber of sweat and exposes it to atmosphere to evaporate away.