density of materials

• solids have strong forces of attraction

  particles don't have much energy and can only vibrate together in their fixed positions

  high density
• liquids have weaker forces of attraction between particles

  they can move past each other and form irregular arrangements

  move random directions at low speed
• gases have almost no forces of attraction between particles so can move freely in random directions at high speeds

  low density
• how do you find the density of an irregular object?

  -measure the mass then submerge it in an eureka can filled with water

  -the water displaced by the object will be transferred to a measuring cylinder

  -u can then use the objects mass and divide it by the volume of the water to calculate its density
• how does colliding gas particles create pressure?

  -particles move at high speeds and collide

  -this exerts a force

  -in a container the pressure is the total force exerted by all the particles in the gas on a unit area of the container walls

  -higher temperature = faster particles = more collisions = increased pressure