MATTER IN OUR SURROUNDINGS : MATTER IN OUR SURROUNDINGS CLASS 9
By ARTI KUSHWAHA
PHYSICAL NATURE OF MATTER : PHYSICAL NATURE OF MATTER Matter is made up of particles.
Particles of matter are continuously moving.
The particles of matter are very small in size.
Particles of matter intermix on their own.
Characteristics of particles : Characteristics of particles Particles of matter have space between them
Particles of matter are continuously moving
Particles attract each other
States of matter : States of matter The solid state
The liquid state
The gaseous state
Slide 5 :
Matter can change its state : Matter can change its state Temperature and pressure determine the state of the matter.
Effect of temperature
Effect of pressure
Effect of temperature : Effect of temperature Melting point
Boiling point
Sublimation
Effect of pressure : Effect of pressure
Changes in states of matter : Changes in states of matter a solid ? a liquid = melting (heat energy added) e.g. ice melts to water
a liquid ? a gas = evaporation (heat energy added) e.g. water to water vapour
a solid ? a gas = sublimation (heat energy added) e.g. dry ice (frozen CO2) to carbon dioxide
a gas ? a liquid = condensation (heat energy removed) e.g. cloud to rain
a liquid ? a solid = freezing (heat energy removed) e.g. water freezes to ice
a gas ? a solid = deposition (heat energy removed) e.g. water vapour to frost
Slide 10 :
Evaporation : Evaporation In liquids, particles from the surface gain enough energy to overcome the forces of attraction present in the liquid and change into the vapour state.
Factors affecting Evaporation : Factors affecting Evaporation The rate of evaporation increases with-
An increase of surface area
An increase of temperature
A decrease in humidity
An increase in wind speed
Two more states of matter : Two more states of matter Plasma
1. the state consists of super energetic and super excited particles.
2. particles remain in the form of ionized gases
3. Plasma glows with a special colour depending on the nature of gas.
4. plasma is created because of very high temperaure and high pressure.
Bose-Einstein Condensate
Bose-Einstein Condensate(BEC) : Bose-Einstein Condensate(BEC) Bose einstein condensate is a new form of matter at the coldest temperature very near to absolute zero.
Atoms in BEC are total opposites to atoms in plasmas
Atoms in BEC are super unexcited and super cold.
In 1924, Albert Einstein and Satyendra Bose predicted the "Bose-Einstein condensate," sometimes referred to as the fifth state of matter.
Finally in 1995, Wolfgang Ketterle and his team of graduate students produced such a condensate experimentally.
Why??? : Why??? We wear cotton clothes in summer.
We see water droplets on the outer surface of a glass containing ice cold water.
Evaporation cause cooling.
Steam produces more severe burns than boiling water.