Bonding + Properties of Matter

• for a substance to change from one state to another energy must be transferred
• the particles gain energy, this results in the breaking of some of the attractive forces between particles during melting
• to evaporate or boil a liquid, more energy is needed to overcome the remaining chemical bonds between the particles
• note the difference between boiling and evaporation, when a liquid evaporates particles leave the surface of the liquid only. when a liquid boils, bubbles of gas form throughout the liquid before rising to the surface and escaping
• the amount of energy needed for a substance to change state is dependent upon the strength of the attractive forces between particles. the stronger the forces of attraction, the more energy needed to break them apart. substances that have strong attractive forces between particles generally have higher melting and boiling points
• the particles in a solid are arranged in a regular pattern. the particles in a solid vibrate in a fixed position and are tightly packed together. the particles in a solid have a low amount of kinetic energy
• Solids have a fixed shape and are unable to flow like liquids. the particles cannot be compressed because the particles are very close together.
• the particles in a liquid are randomly arranged, the particles in a liquid are able to move around each other. the particles in a liquid have a greater amount of kinetic energy then particles in a solid
• liquids are able to flow and can take the shape of the container that they are placed in, as with a solid liquids cannot be compressed because particles are close together
• the particles in a gas are randomly arranged, the particles in a gas are able to move around very quickly in all directions. of the three states of matter gas particles have the highest amount of kinetic energy
• gases are able to flow and can fill the container they are placed in, the particles are far apart which allows them to move in any direction
• gases can be compressed when squashed the particles have empty space to move into
• what are the limitations of the particle model?


  chemical bonds between particles are not represented, particles are represented as solid spheres (this is not always the case), particles like atoms are mostly empty space, particles are not always spherical in nature.
• solid = S

  liquid = L

  gas = G

  aqueous = Aq
• identification of the physical state?


  if the given temperature is below the melting point, the physical state of the substance is solid

  if the given temperature is between the melting and boiling point, the physical state of the substance is liquid

  if the given temperature is higher than the boiling point, the physical state of the substance is gas
• ions are charged particles, they can be either positively or negatively charged
• when an element loses or gains electrons it becomes an ion, metals lose electrons (positive) non metals gain electrons (negative)
• group 1 and 2 lose electrons and group 6 and 7 gain electrons
• group 1 = +1 ion

  group 2 = +2 ions

  group 6 = -2 ions

  group 7 = -1 ion
• metals are strong shiny malleable and good conductors or heat and electricity
• non metals are brittle dull and not always solid at room temp and poor conductors of heat and electricity
• metallic bonding?

  • between metals only
  • positive metal ions surrounded by a sea of negatively charged delocalised electrons
  • ions are tightly packed and arranged in rows
  • strong electrostatic forces