T2: Separating Techniques

• Compound vs. Mixture



  Different: chemically bonded vs. physically mixed substances
• Mass Number



  Total protons and neutrons in an atom's nucleus
• Sub-atomic Particles



  Protons, neutrons, electrons in an atom
• Neutral Atoms


  Equal protons and electrons cancel out charges
• Atomic Structure


  Arrangement of electrons in an atom's charge
• John Dalton


  First modern atom advocate, indivisible particles concept
• Js Thomson


  Discovered electrons, proposed plum pudding model
• Ernest Rutherford 


  Identified nucleus, planetary model, discovered proton
• Niels Bohr


  Introduced electron shells concept in atomic structure
• James Chadwick


  Discovered the neutron, a neutral particle in the nucleus
• Alpha Particle


  Helium nucleus with 2 protons, 2 neutrons, +2 charge
• Plum Pudding Model


  JJ Thompson's atom model with embedded electrons in positive charge
• Rutherford‘s Experiment 


  Firing alpha particles at gold foil, proved mostly empty space
• Particle Model


  Representation of matter as particles with defined properties
• Limitations of particle model

  Particles only vibrate, slide past each other, no attractive forces considered
• Solid in a particle model

  Particles touch, regular arrangement, do not take into account attractive forces
• Liquid in a Particle model

  Particles touch, random arrangement, do not consider particle size
• Gas in a particle model

  Particles very spread out, move quickly in all directions
• Volume Increase


  Occurs when substance melts or boils, attractive forces overcome
• Iron melting


  Volume increase indicates distance and attractive forces change
• Water freezing


  Water expands when freezing due to unique molecular structure
• Particle attraction


  Distances between particles affect force of attraction
• States of Matter


  Three main forms: solid, liquid, gas
• Solid


  Particles touch regularly, vibrate in place
• Liquid


  Particles touch randomly, move and slide past each other
• Gas


  Particles very spread out, move very quickly in all directions
• Condensation


  Gas to liquid phase change
• Sublimation


  Solid to gas phase change
• Deposition 


  Gas to solid phase change
• Solid attractive forces


  Strongest attractive forces between particles
• Gas attractive forces 


  Weakest attractive forces between particles
• Particle compression 


  Solid particles can be compressed due to space between them