Grade 8 Science Unit 4

• The three most familiar states of matter

  solid, liquid, gas
• Describe the particles in solids

  Particles are close together and vibrate in place.
• Describe the particles in liquids

  Particles are close together but can slide past one another
• Describe the particles in gases

  Particles of a gas are far apart and move independently of one another
• Solid


  The state of matter that has a definite volume and shape of a substance are fixed (which means it never changes)
• Liquid


  The state of matter that has definite volume but not a definite shape. Liquid takes the shape of the container its in
• Surface tension


  The force that acts on the surface of a liquid and that tends to minimize the area of the surface
• Viscosity


  The resistance of a gas or liquid to flow
• Gas


  A form of matter that does not have a definite volume or shape
• What matter is made up of

  molecules and atoms
• change of state

  When a substance changes from one physical form to another
• The five changes of state

  Melting, Freezing, Evaporation, Condensation, Sublimation
• Gallium


  melts at 30 degrees celcius, not good for jewelry
• Melting Point


  The temperature at which a substance changes from solid to liquid
• Endothermic change


  Energy is gained by the substance as it changes state (like melting)
• Freezing Point


  the temperature at which it changes from a liquid to a solid
• What happens if energy is added or removed from a glass of water


  the ice cube will melt and when energy is removed the water will freeze
• exothermic change


  energy is removed from the substance (like freezing)
• Atmospheric pressure


  decreases as you go higher above sea level and the temperature of a substance gets lower
• condensation


  The change of state from a gas to a liquid
• Boiling point

  at a given pressure, the condensation point for a substance is the same as this
• Evaporate


  happens when a substance changes from a gas to a liquid
• Solid Carbon Dioxide


  Dry ice - instead of melting into a liquid it goes through sublimation
• Sublimation


  The change of state from a solid to a gas
• The speed of the particles in a substance changes when the what changes?

  temperature
• The temperature of a substance does not change before the what is complete?

  Change of state
• The three most familiar states of matter

  solid, liquid, gas
• Describe the particles in solids

  Particles are close together and vibrate in place.
• Describe the particles in liquids

  Particles are close together but can slide past one another
• Describe the particles in gases

  Particles of a gas are far apart and move independently of one another
• Solid


  The state of matter that has a definite volume and shape of a substance are fixed (which means it never changes)
• Liquid


  The state of matter that has definite volume but not a definite shape. Liquid takes the shape of the container its in
• Surface tension


  The force that acts on the surface of a liquid and that tends to minimize the area of the surface
• Viscosity


  The resistance of a gas or liquid to flow
• Gas


  A form of matter that does not have a definite volume or shape
• What matter is made up of

  molecules and atoms
• change of state

  When a substance changes from one physical form to another
• The five changes of state

  Melting, Freezing, Evaporation, Condensation, Sublimation
• Gallium


  melts at 30 degrees celcius, not good for jewelry
• Melting Point


  The temperature at which a substance changes from solid to liquid