UTS 306K Review

• Matter

  • Has mass
  • Takes up space
• Non-examples of matter

  • Light
  • Gravity
• Why light and gravity are non-examples of matter

  They do not have mass or take up space
• Why solids, liquids, and gases are examples of matter


  They have mass and take up space
• Model


  A representation of what is happening that we can't see with the naked eye
• Models are not exact
• Examples of models


  • Sand and pebble experiment
• What the sand and pebble experiment was a model of

  Particulate nature of matter
• Law of Conservation of Mass


  Mass can't be created or destroyed; only conserved
• Matter is particulate, not continuous
• Experiment that proved matter is particulate

  • Water and ethanol
• What it means for matter to be particulate


  At one point, you cannot break down a substance further without changing the nature of the substance
• Particle interactions


  Non-contact interaction
• What holds all matter together

  Electric/electrostatic force
• Electrostatic potential energy


  The energy change between two charged particles moving apart or together
• Opposites charges attract, like charges repel
• As the spacing between particles increases

  Electrostatic potential energy increases
• Electrostatic potential energy and magnetic potential energy


  They are similar
• Electrostatic potential energy is stronger than gravity
• Water


  • Strongest attraction between particles
  • Polar
• Hexane


  • Weakest attraction between particles
  • Symmetric
• Ethanol


  • Some/medium attraction between particles
  • Bigger molecule so the attraction isn't as strong
• Charges cannot be created or destroyed, but they can be transferred
• Law of conservation of charge


  The idea that charges cannot be created or destroyed
• Mass


  How much stuff something is made up of
• Volume


  How much space something takes up
• There is nothing, no air, between particles</b>
• Particle motion in liquids and gases


  Particles move at different speeds individually (but same speed ON AVERAGE)
• Particle motion in solids


  Particles vibrate in place but are fixed in position
• Density formula


  D = Mass/Volume
• The ratio of mass over volume (density) will be the same at the same temperature and pressure for objects of the same substance but different shapes
• Gas


  • Least dense
  • Particles move freely
  • Weak to non-existent forces between particles
• Liquid


  • Medium dense
  • Particles flow past each other
  • Medium strength forces between particles
• Solid


  • Most dense
  • Regular arrangement
  • Particles vibrate in position
  • Strong forces between particles
• If mass and volume both increase for an object of the same substance, the density will remain the same
• As volume increases


  Density decreases
• As volume decreases


  Density increases
• As temperature increases


  Average kinetic energy increases
• As temperature decreases


  Average kinetic energy decreases
• Evaporation


  • Can occur at any temperature
  • Surface effect
  • Usually a slow process