Chemistry Yr9

• halogen


  an element in Group 7
• diatomic


  elements that go round in pairs like Cl2, H2
• examples of diatomic elements

  all gas elements that are not noble gases (hydrogen, oxygen, nitrogen) plus all of group 7
• Alkali metal


  element in Group 1
• Observations when an alkali metal reacts with water (e.g. lithium)


  fizzing, moving on the surface, white trail, metal disappears
• Extra observation when sodium reacts with water

  melts into a ball
• Extra observation when potassium reacts with water

  produces a lilac flame and reacts very fast
• Trend in reactivity down group 1

  reactivity increases
• Trend in reactivity down group 7

  reactivity decreases
• Trend in melting point down group 7

  melting point increases
• Reason for increased reactivity down Group 1

  more shells of electrons

  outer electron further from the nucleus

  less attracted so easier to lose
• Colour and state of iodine

  grey solid
• Colour and state of chlorine

  green gas
• Colour and state of bromine

  red-brown liquid
• Colour of iodine solution

  brown
• Colour of bromine solution

  yellow/orange
• Colour of chlorine solution


  colourless
• Displacement reaction


  reaction where a more reactive element displaces a less reactive element from a compound
• flame colour for sodium

  yellow flame
• flame colour for lithium

  red flame
• flame colour for calcium

  brick-red flame
• flame colour for potassium

  lilac flame
• solid


  The particles are tightly packed.

  
  

  The particles do not move around.

  
• liquid


  The particles are close together.

  
  

  The particles vibrate, move, and slide past each other.

  
• gas


  The particles are very separated.

  
  

  The particle vibrate and move quickly.

  
• gas


  A state of matter that has no definite shape or volume. Has a high kinetic energy.

  
• sublimation


  Solid to Gas
• deposition


  gas to solid
• Condensation


  gas to liquid
• Evaporation


  liquid to gas
• Freezing


  Liquid to Solid
• Melting


  Solid to Liquid
• solute


  the substance that is dissolved
• solvent


  the liquid in which the solute dissolves in
• Solution


  made when a solute dissolves in a solvent
• saturated solution


  a solution that cannot dissolve any more solute under the given conditions
• dilution


  adding more water to a solution causing the solute particles to spread out further apart therefore the colour fades but not disappear
• a net flow of matter from an region of high concentration to an area of low concentration

  dilution
• Higher concentration


  Darker colour
• Lower concentration 


  Lighter colour