c1

• what is the structure of particles in a solid?

  regular arrangement, very close together, vibrate around fixed positions
• what is the structure of particles in a liquid?

  random arrangement, close together, move around eachother
• whats the structure of particles in a liquid?


  random arrangement, far apart, move in all directions quickly
• disadvantage of 2D particle models

  may not show 3D structure
• disadvantage of 3D particle models

  more difficult to create
• 3 disadvantages of 2D and 3D particle models

  don't show how they are moving, not to scale with respect to the particles, don't show the forces of attraction
• solid to a liquid

  melting
• liquid to a solid


  freezing
• liquid to a gas

  evaporation
• gas to a liquid

  condensation
• solid to a gas

  sublimation
• gas to a solid

  depositation
• chemical change


  produces one or more new substances and irreversible
• physical change


  when a substance changes state or shape, or breaks into pieces (no new substances are made), reversible change
• electrostatic forces of attraction


  the forces which attract particles together
• what happens when particles gain heat energy

  it makes them move faster giving them kinetic energy
• ration of distance to diameter=

  distance between atoms/diameter of atom
• 3 limitations to particle models

  the forces between particles, the size of particles, the space between particles
• why to atoms have no charge

  because they have the same number of protons as electrons and protons are positive and electrons are negative so cancel each other out
• ion


  when an atom has lost or gained electrons
• what happens when an atom has a full outershell

  the become stable and unreactive
• isotope


  atoms with the same number of protons but a different number of neurtons
• pure


  when a substance is made up of a single element or compound
• solution


  when a substance is dissolved into another
• solute


  the substance that disolves
• solvent


  the substance the solute dissolves into
• soluble


  it can dissolve
• insoluble


  it cannot dissolve
• saturated


  when no more solute can dissolve into the solvent at that temprature
• whats filtration used for

  separate an insoluble solid from a liquid and to purify a mixture
• distillation


  used to separate mixtures that contain liquids
• fractional distillation


  used to separate a mixture of liquids with similar boiling points
• chromatography


  used to separate and identify substances in a mixture.
• mobile phase


  where the molecules can move, always in a gas or liquid state
• stationary phase

  where the molecules can't move, solid or a really thick liquid
• RF


  distance travelled by the substance/distance travelled by solvent
• relative atomic mass


  the mean mass of an atom of an element compared to 1/12 the mass of a carbon 12 atom
• relative formula mass

  the mean mass of a substance compared to 1/12 of the mass of a carbon 12 atom
• gas chromotography

  used to analyse unknown substance (must be vaporised)
• empirical formula

  shows the simplest whole numbers ratio of the atoms of each element in a compound