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Matter mostly exists is one of three states or phases : solid, liquid or gas. An increase or decrease in energy (temperature) can lead to a change of phase. Changes of State. Sublimation (Deposition) : Change from gas directly to a solid or from a solid directly to a gas . - PowerPoint PPT Presentation
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Changes of StateMatter mostly exists is one
of three states or phases:
solid, liquid or gas.
An increase or decrease in
energy (temperature) can lead to a
change of phase.
Sublimation (Deposition): Change from gas directly to a solid or from a solid directly to a gas.
Types of Changes of State
SOLID LIQUIDGAS
Melting: Change from solid to
liquid.
Vaporization/Evaporation: Change from liquid to gas.
Solidification/Crystallization
(freezing): Change from liquid to solid.
Condensation: Change from gas to liquid.
Stored Heat and Changes of State
When an object is in one of the three states, its temperature rises as thermal energy is
added to it.
If an object is in the process of changing
its state of matter, the temperature remains the same as thermal energy is added to it.
When an object is in one of the three states, its temperature rises as thermal energy is
added to it.
SOLID BASALT LIQUID BASALT
THERMAL ENERGY THERMAL ENERGY
Temperature rises
Temperature rises
Melting/Solidification
Stored Heat and
Changes of State
When an object is changing phase, the thermal energy added to it does not increase the temperature of the object.
The added thermal energy becomes a form of stored or potential energy. This is also known as latent heat.
SOLID BASALT LIQUID BASALT
THERMAL ENERGY THERMAL ENERGY
Melting/Solidification
In order for an object to change phase from: solid liquid gas
The object GAINS stored HEAT ENERGY
In order for an object to change phase from:gas liquidsolid
The object MUST RELEASE its stored HEAT ENERGY
What happens to the thermal energy of the solid
basalt when it melts?
When the basalt melts the thermal energy will not
raise the temperature of the rock. Instead the rock
will gain stored heat energy.
Stored Heat and Changes of State of Water
Gain Heat Energy
Lose Heat Energy
How long did it take for the water sample to boil?
4 minutes.
How long was the change of state for the water sample from liquid to gas (vapor)?
4 minutes
What happens to the heat energy added to the water sample after 4
minutes into the experiment?
The added heat energy did not change the temperature of the
water. Heat energy was absorbed and stored as the water changed
state from liquid to gas.
Stored Heat and Changes of State of Water Heat gained during
vaporization: 2260 J/g
Heat released during condensation: 2260 J/g
Heat released during freezing: 334 J/g
Heat gained during melting: 334 J/g
RT = Pg. 1
Earth’s Energy Supply: Solar Energy
The majority of Earth’s energy comes from the Sun.
The sun “radiates” all forms of electromagnetic energy including visible light (greatest intensity).
NOTE** Deuterium and Tritium are two forms of hydrogen.
Solar energy is a product of nuclear fusion. In nuclear fusion, two light elements (hydrogen) are
combined to form one heavier element (helium) under
tremendous amounts of heat and pressure.
The process of nuclear fusion produces a great amount of energy
– including the electromagnetic energy that is radiated to Earth.
Earth’s Energy Supply: Earth’s Interior Some of Earth’s energy comes from the planet itself.
Heat from the Earth can be changed to kinetic energy as
mountains are made and volcanoes erupt.
The Earth still is generating heat from its own creation some 4.5 billion years ago (Earth’s core). The core is the source of gravity for the planet. Materials being
pulled towards the center of the Earth generate energy.
Most energy created in Earth’s interior is from nuclear decay or
nuclear fission.
Nuclear fission is the opposite of nuclear fusion. In nuclear fission a heavier, unstable element (uranium) “decays” or
is broken down into two lighter elements (rubidium and cesium). This process releases a large amount of energy.
Today’s nuclear reactors use this same process as an alternative energy source to the burning of fossil fuels.