HEAT / THERMAL ENERGY

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HEAT / THERMAL ENERGY
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Phase Changes -Melting, Freezing, Evaporation,
Boiling, Condensation, Sublimation
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http//www.brainpop.com/science/energy/temperature
/
Temperature
the measure of the average kinetic energy of the
particles in an object
absolute zero the temperature at which molecular
motion stops.
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Heat
http//www.brainpop.com/science/energy/heat/
the energy transferred between objects that are
at different temperatures
Heat is always transferred from the object that
has the higher temperature to the object that
has the lower temperature
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When matter is heated, the molecules react by..
-Speeding up
-Spreading out
This is known as thermal expansion -The increase
in volume (size) due to added heat.
Thermal heat Expand to get bigger
When matter is cooled, the molecules react by..
-Slowing down
-Contracting
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Conduction
Transfer of heat / energy through direct
contact -Occurs best in solids
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Conductors
Insulators
Wood
Metal Objects
Glass
Water
Cotton
Rubber
Air
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Convection
Transfer of heat / energy through liquids and
gases
-Involves circular currents based on density of
cooler / warmer matter
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Radiation
Transfer of heat / energy through open space
-Radiate To Give Off
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Light Energy radiated from the sun
Only about half the energy from the sun reaches
Earth. The other half is either reflected away
or is absorbed by other factors
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The Greenhouse Effect
Warming that results when solar radiation is
trapped by the atmosphere caused by atmospheric
gases that allow sunshine to pass through but
absorb heat that is radiated back from the warmed
surface of the earth
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Brainpop greenhouse effect
OZONE
Ozone is a gas made up of three oxygen atoms
(O3). It occurs naturally in small (trace)
amounts in the upper atmosphere (the
stratosphere). Ozone protects life on Earth
from the Suns ultraviolet (UV) radiation.
Pollution is depleting it upsetting the natural
balance of good ozone at the stratospheric
level of the atmosphere
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