matter

• A phase change is a physical process in which a substance goes

  from one phase to another.
• Usually the change occurs when

  adding or removing heat

  at a particular temperature, known as the

  melting point or the boiling point

  of the substance. (phase change)
• The melting point is the

  temperature at which the substance

  goes from a solid to a liquid
• The boiling point

  is the temperature at which a

  substance goes from a liquid to a

  gas
• A phase is a form in which a substance exists.
• Best describes matter?

  occupies space and mass
• Not example of matter

  • sound
• Not matter

  light, shadow, feeling
• True regarding particle nature of matter -particle move all the time
• Gas has the weakest force of attraction between particles
• Attractive force of liquid particles when they're cooled strengthen
• Gas particles are not attached & moving rapidly
• Solid particles are held together by strong attractive force
• Liquids have definite volume but indefinite shape because theyre free to move easily and held by less attractive force
• Freezing: Change of a substance from liquid phase to solid
• Melting: Change from solid phase to liquid
• Vaporization: Change from liquid to gas form
• Condensation: Change from gas to liquid form
• Sublimation: Change from solid to a gas without becoming a liquid
• Deposition: Change from gas to solid without becoming a liquid
• lonization: Change from a gas phase to plasma (ionized particles)
• Recombination: Change from plasma to gas
• Solids have high melting and boiling points.
• Liquids have comparatively low melting and boiling points.
• Gases have extremely low melting and boiling points