Periodic Table/Chemical Reactions

• displacement reaction - when a more reactive element takes place of a less reactive element in the compound

  e.g.

  tin sulphate + potassium -> potassium sulphate + tin

  because: potassium is more reactive than tin
• Group 1 metals are called alkalis. They are very reactive metals that get more reactive as you go down the group.
• Group 7 elements are called halogens. They are very reactive and gets less reactive as you go down the group.
• Group 0/8 elements are called the noble gases. They are unreactive(inert).
• The melting and boiling points of Group 1 elements, decrease as you go down the group.
• Diatomic molecules exist as two atoms (e.g. F2).
• The melting and boiling points of Group 7, increase as you go down the group.
• exothermic reactions - transfer heat energy to the surroundings

  e.g. neutralisation
• endothermic reactions - take in heat energy from the surroundings

  e.g. thermal decomposition
• temperature change = final temp - starting temp
• calorimetery - technique where food is burnt to see how much it heats up water
• The reactivity series is a list of metals according to their reactivity.
• most reactive -> potassium

  -> copper

  -> silver

  -> gold

  least reactive -> platinum
• displacement reaction - when a more reactive element takes the place of a less reactive element in the compound

  e.g. tin sulphate + potassium -> potassium sulphate + tin
• Metals are found in the earth's crust.

  metal + oxygen -> metal oxide
• reduction - the removal of oxygen

  metal oxide + carbon -> metal + carbon dioxide
• 3 -> atomic mass = protons + neutrons

  Li -> symbol (lithium)

  7 -> atomic number = protons = electrons
• 1st shell - max of 2 electrons

  2nd shell - max of 8 electrons

  3rd shell - max of 8 electrons
• polymer - a large molecule made up of many monomers

  e.g. polymerization reaction:

  A) double bond

  B)

  C) polymer