Chemistry

• Solids

  Particles in fixed arrangements, vibrate around fixed positions, have little kinetic energy, strong forces between them
• Liquids

  Particles slightly more widely spaced, not touching as much, have intermediate forces between them, vibrate more, no fixed positions
• Gases

  Particles further apart, have large amounts of kinetic energy, not held in fixed positions, weak forces between them
• Conversions between states of matter

  1. Melting (solid to liquid)

  2. Freezing (liquid to solid)

  3. Boiling/Evaporating (liquid to gas)

  4. Condensation (gas to liquid)
• Particles with most kinetic energy evaporate first, leaving remaining particles with lower average kinetic energy
• In a closed container, condensation and evaporation occur simultaneously
• Diffusion


  Net movement of particles from an area of high concentration to an area of low concentration, down the concentration gradient, no energy required, passive process
• Diffusion example

  • Ammonia and hydrochloric acid in a glass tube, forming ammonium chloride ring
• Solute


  Solid which dissolves in a solvent
• Solvent


  Liquid in which the solute dissolves
• Solution


  Mixture of solvent and solute
• Saturated solution


  Solution where no more solute can be dissolved in the solvent
• Atom

  Smallest particle of a substance that can exist
• Element


  Contains only one type of atom, cannot be split by chemical means
• Compound


  Two or more elements chemically combined, cannot be separated back into constituent elements
• Mixture


  Two or more elements not chemically combined, can be separated into constituent components
• Pure substance


  Contains only one type of material, has a fixed boiling point
• Filtration


  Separates insoluble solute from solvent
• Evaporation


  Separates soluble solute from solvent
• Separating immiscible liquids


  Using a separating funnel
• Simple distillation


  Separates liquids of different boiling points
• Fractional distillation


  Separates many liquids of different boiling points
• Chromatography


  Separates liquids of different solubilities
• Molecule


  Two or more atoms bonded together
• Proton

  Positive charge, mass of 1
• Neutron

  Neutral charge, mass of 1
• Electron

  Negative charge, mass of 1/2000
• Atomic number


  Number of protons in an atom
• Mass number


  Total number of protons and neutrons in an atom
• Isotopes


  Atoms of the same element with the same number of protons but different number of neutrons
• Calculating relative atomic mass of isotopes


  Multiply each isotope's mass by its percentage abundance, add together, divide by 100
• Relative atomic mass


  Ratio of the average mass of an element compared to one atom of carbon-12
• Group number


  Number of electrons in the outer shell of an element
• Period number


  Number of electron shells in an atom
• Noble gases


  Group 0 elements, highly unreactive due to full outer electron shells
• Metals


  High melting/boiling points, good conductors, shiny, sonorous, malleable, ductile, form positive ions, form basic oxides, participate in ionic bonding
• Non-metals


  Low melting/boiling points, dull, brittle, form negative ions, form acidic oxides, participate in covalent and ionic bonding
• Ion


  Charged particle formed by gaining or losing electrons
• Balancing chemical equations using the method of multiplying reactants/products by appropriate factors
• Electrons to become positive ions they form basic oxides which will come in to later and they partake in ionic bonding