y3 Che. 1 & 2

• pure substances


  1 type of molecule
• mixture


  different types of molecules
• macro level


  on big scale
• micro level


  on small scale
• solid --> gas

  sublimation
• gas --> solid

  deposition
• solution


  liquid + g,l,s dissolved
• suspension


  liquid + solid not dissolved
• emulsion


  liquid + liquid not dissolved
• homogeneous 


  can't tell substances appart
• hetrogeneous


  can tell substances appart
• sedimentation


  denser substance goes down
• centrifugation


  sped up sedimentation by spinning
• filtering


  some substances fit through filter paper
• evaportaion


  water in mixture evaporates
• distillation


  sped up evaporation by bunsin burner + lowest boiling point evaporates
• extraction


  soluble substance seperates from insoluble substance (tea)
• adsorption


  some substances stick to a surface
• paper chromatography


  difference in sollubility
• concentration = mass / volume
• mass percentage = mass substance / mass mixture x 100%
• diatomic atoms


  H2, N2, O2, F2, Cl2, Br2, I2
• thermolisis


  decomposition by heat
• photolysis


  decomposition by light
• electrolysis


  decomposition by electricity
• combustion reaction


  reacts with oxygen
• complete combustion

  enough O2, makes CO2
• incomplete combustion

  not enough O2, makes CO
• Reagents


  reacts visibly with substance