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Sizzling physics
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Thursday, September 4, 2008 @ 5:36 AM
THERMAL PROPERTIES OF MATTER
Internal energy is the total energy of the particles(which is held by intermolecular bonds).It is made up of the kinetic energy component and the potential energy component.The kinetic component is because of the vibration of particles relating to temperature.The potential component is because of the stretching and compressing of intermolecular bonds as particles vibrate.
-melting-
melting occurs at constant temperature for pure substances also known as the MELTING POINT.Thermal energy is needed to break the intermolecular bonds of molecules to allow the solid to melt.Thermal energy is absorbed by the substance.
-solidification and freezing point-
it is the change of a liquid state to a solid state.It will solidify at the same temperature as the melting point.there is no change in temperature during solidifiaction.
-Boiling and Condensation-
Boiling is the change of liquid state into vapour state at a fixed temperature(boiling point).Thermal energy is absorbed.Condensation is the opposite.The change of vapour state to liquid state at the same temperature as in boiling.Thermal energy is given out during condensation.
-evaporation-
It is the change of liquid state to gaseous state.It is similar to boiling but the difference is that evaporation can occur at any temperature.There are some factors that affects the rate of evaporation:
1.Temperature
-raising temperature=increase rate of evaporation
2.Humidity of surrounding air
-The rate of evaporation increases with lower humidity(Pr essence of water vapour in air)
3.surface area of liquid
-more exposed surface area=increase rate of evaporation
(because evaporation occurs at the exposed surface of the liquid only)
4.Movement of air
-surrounding air moving increase rate of evaporation.
5.Pressure
-reducing atmospheric pressure=increase rate of evaporation
6.Boiling point of the liquid
Different liquids have different boiling points.Liquids with lower boiling points will evaporate faster.
We have now come to an end of learning the thermal properties of Matter!!So exhausted already!!:)
