This page contains the detailed and easy notes for GCSE OCR 21st Century Physics Matter -model and explanations for revision and understanding Matter -model and explanations .
Matter -model and explanations
When the particle is cooled, it looses
energy and the particles move closer.
Melting Point
It is the temperature at which the ice
melts from solid to liquid without the change
in temperature. For water it is 0 degrees.
Boiling Point
It is the temperature at which the water
boils from liquid to gas without the change
in the temperature. It is 100 degrees for
water.
Freezing Point
It is the temperature at which the water
freeze from liquid to solid to form ice without
the change in temperature.For water it is 0 degrees.
When we heat the ice :-
a) The ice is heated. The temperature increases
to zero degrees. At zero degrees, the melting
point is reached.
b) At the melting point, the ice melts to form water.
At this stage there is no change in the temperature
and if we plot the graph then it will be the flat
section of the graph.
c) After the ice is melted and forms liquid, the liquid
is heated again until it reaches its boiling
point at 100 degrees.
d) At the boiling point, the water boils to form the gas or
water vapor without any change in temperature.
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Energy stored by the particle of a substance
KINETIC ENERGY
It is the energy due to the particle’s
individual motion relative to each other.
POTENTIAL ENERGY
It is the energy due to the particle’s
individual position relative to ach other.
Heating or cooling a particle changes its internal energy and
changes the state of the particle.
It is the energy transferred when the substance changes its state without
the change in temperature.
Plot the graph of temperature changes with time
for a given mass of ice let’s say 100 g of ice with
the power supply of 50 W. Note the time
for which the temperature did not change but change
of state take place.
LATENT HEAT OF FUSION
Power= 50 W
Time= 60 minutes= 3600 seconds
E= Power X time
= 3600 X50
LATENT HEAT OF VAPORIZATION
It is the amount of heat required to raise the temperature
of 1 Kg of a substance by 1 degrees celcius.
Calculate the total energy required to convert to 750 g of water
at 50 degrees to 120 degrees. Specific Heat capacity
of water = 4200 J/Kg/C and latent heat of vaporization 2,260 KJ/Kg ?
Increasing the temperature
increases the kinetic energy of the molecules
So, the particles collide more and increases
the pressure.
For a fixed amount of gas at a given temperature,
the product of Pressure and Volume is constant.
volume of 20 m3, then how much
volume it will occupies if it is compressred
to 10 KPa.
Make sure you have watched the above videos and are familiar with the key definations before trying these questions. It is also good to time yourself while doing these questions so that you can work on the speed as well.