Chemistry paper 1

• what is the electronic structure

  2 8 8
• what are protons size and electrical charges

  1

  +1
• what are electrons size and electrical charges

  very small

  -1
• what are neutrons size and electrical charges

  1

  0
• what are compounds

  they are chemically combined
• what are mixtures


  not combined and can be separated
• how can mixtures be separated

  fractional distillation

  crystallisation

  filtration

  chromatography
• plum pudding model


  developed by JJ thompson

  ball of positive charge with negative charge embedded
• alpha scattering 


  rutherford

  found that the mass was concentrated in the nucleus
• what did neils bohr discover

  electrons orbit the nucleus at specific distances
• what did chadwick discover

  there are neutrons within the nucleus
• mendeleev


  left gaps on the periodic table

  correctly predicted the properties
• group 1 electrons

  single electron in outer shell

  creates an alkali solution when reacting with water

  reacts with oxygen to form oxide

  reacts with chlorine to form white precipitate
• why do group 1 elements increase in reactivity as they go down the group


  the distance between the furthest electron and the nucleus increases

  so there is less attraction

  so the atom loses an electron more easily
• group 0- noble gases

  unreactive due to full outer shell

  boiling point increases as you go down the group because the relative atomic mass increases
• group 7 - halogens

  have similar reactions because they have the same number of outer shell electrons

  diatomic

  down group= MP and BP increases

  reactivity decreases going down the group
• compared to group 1 transition metals are

  harder

  stronger

  high MP

  high density

  less reactive
• properties of transition metals

  form ions with different charges

  form coloured compounds

  are useful catalysts
• chromium 


  ions = +2, +3, +4, +5, +6

  +2= blue

  +3= green

  +6= orange
• manganese

  ions= +2,+3,+4,+5,+6,+7

  +2= pink

  +4= red

  +5= green

  +7= purple

  used for decomposition of hydrogen peroxide
• iron 


  ions = +2, +3, +4, +5, +6

  +2= green

  +3= yellow

  used for the haber process
• colbolt

  ions = +2, +3, +4, +5,

  +2= pink

  +3= green
• nickel


  ions = +2, +3, +4,

  +2= green

  used to make margarine
• copper

  ions = +1, +2, +3,

  +2= blue
• what is ionic bonding

  electrostatic attraction between oppositely charged ions

  non metal and metal
• what is covalent bonding

  shared pair of electrons

  metal and metal
• what is metallic bonding


  forces of attraction between delocalised electron and the nucleus of a metal ion
• ionic bonding 


  outer shell electrons are transferred and creates ions

  if they loose an electron they are a positive ion

  if they gain an electron they are a negative ion
• giant ionic structures


  giant structure of ions held together by forces of electrostatic attraction

  they have high melting points

  dont conduct when solid

  do conduct when molten as electrons are free to move
• giant covalent structures


  solids in a giant lattice

  do not conduct because they have no delocalised electrons

  strong bonds so high melting and boiling point
• simple covalent structures


  dont conduct electricity

  small molecules

  weak intermolecular forces so low melting and boiling points
• metallic bonding


  positive ions and delocalised electrons arranged in a regular pattern

  strong bonds

  do conduct as the electrons can move through the structure
• properties of metals


  high melting and boiling point as they have strong forces of attraction

  good thermal conductors

  malleable
• what are alloys


  mixture of different metals which are different sizes that distort layers so they cannot slide making them harder
• fullerenes

  c60

  hollow and spherical structure made of hexagonal rings
• graphene

  single layer of graphite

  useful for electronics and composites
• diamonds

  4 strong covalent bonds for each C atom

  very hard

  dont conduct

  high melting points
• graphite

  3 covalent bonds for each C atom

  layers of hexagonal rings

  high melting points

  layers can slide as they have weak intermolecular forces

  conduct thermal electricity
• nanotubes

  cylindrical fullerene which has a high length to diameter ratio

  high tensile strength

  conduct

  used for drug delivery and suncreams
• what is the conservation of mass

  no atoms or lost or gained during a reaction so the mass of products= the mass of reactants