Discovery Education Video:A Closer Look at the
States of Matter
Take a more detailed look at each state of matter and its specific properties.
Objects and substances can be changed as they gain or lose
thermal energy.
Changes in state are one very clear change that can be
observed.
As a substance continues to gain heat energy, it will transition
toward becoming a gas.
As the substance becomes warmer, its molecules will move faster and
expand, or spread farther apart.
As a substance continues to lose heat energy, it will transition
toward becoming a solid.
As the substance loses thermal energy,
its molecules will move slower and contract, or come closer together.
Solid Liquid Gas
Melting Boiling
Freezing Condensation
Sublimation
Deposition
Changes in States of Matter
Discovery Education Video:States of Matter: Dry Ice
Jeff and Matt demonstrate the explosive power of dry ice. As the frozen carbon dioxide changes from a solid
to a gas, the gaseous CO2 expands to fill up its container.
Discovery Education Video:Liquid Nitrogen: States of Matter
The program presents the properties of nitrogen in both its liquid and gaseous states. As a liquid, nitrogen is able to freeze
almost any object. The team films the changes that occur to normally flexible objects after being submerged in liquid
nitrogen and dropped onto the laboratory table. Additionally, the team experiments with what happens to liquid nitrogen in a sealed bottle as it warms up to room temperature and becomes
a gas.
Expansion and contraction of materials
must be taken into account during
construction projects.
Expansion joints allow bridges to
expand or contract depending on their
temperature.
Discovery Education Video:Expansion and Contraction
Expansion and contraction occurs when an object is cooled or heated. Designers must take this into account
when building bridges and other structures.
Discovery Education Video:How Heat Affects Expansionand Contraction of Matter
This video clip explains that most matter expands when heated and contracts when cooled. However, water does the
opposite, it expands when it freezes to ice, and contracts when warmed. Temperature is measured by thermometers
by using either Celsius, or Fahrenheit degrees.