particle model & motion in gases

• | solids

  • strong forces of attraction holding particles close together
  • fixed, regular arrangement
  • not much energy so can only vibrate in fixed positions
• | liquids

  • Weaker forces of attraction holding particles
  • particles are close but can move past each other
  • more energy & can move in random directions @ slow speeds
• | gases

  • almost no forces of attraction
  • more energy & r free to move in random directions and speeds
• Do liquids move in fast or slow speeds?

  slow
• | pressure

  • gas particles can move around
  • when they collide with something, they exert a force
  • pressure of the force exerted per unit area
  • in a sealed container, gas pressure is TOTAL force exerted by all particles on a unit area of the container walls
• what is pressure?

  the force exerted per unit area
• what is pressure?

  force exerted per unit area
• what is pressure?

  force exerted per unit area
• what is the force exerted per unit area referred as?

  Pressure
• what is the force exerted per unit area referred as?

  pressure
• what is the force exerted per unit area referred as?

  Pressure
• what is pressure

  Force exerted per unit area
• solids are in … arrangements

  fixed
• gases have almost … forces of attraction

  no
• go gas particles have any forces of attraction

  No
• at which directions do gas particles move in

  random
• | temperature & pressure

  • increasing temperature means You transfer energy into the kinetic store of particles
  • higher temperature means average speed of particles increase
  • for a gas at constant volume, this increases pressure
  • particles travelled QUICKER, so they hit sides often in a given amount of time
  • particles have larger momentum so they exert larger force