Paper 1

• Element:

  a substance containing one type of atom
• Compound:

  A substance containing two or more different types of atoms chemically bonded
• Conservation of mass:

  Atoms can neither be created or destroyed in a reaction it must be balanced
• Mixture:

  Diffrent substances not chemically bonded
• Filteration:

  Removes large insoluble particles from a liquid
• Evaporation:

  Leaves behind crystals of a dissolved substance if heated gently
• Chromatography:

  Causes substances to rise up due to

  Capillary action:

  Lighter particles move further up
• Distilation:

  Involves condensing the evaporated solvent and collecting it
• Fractional distilation:

  Can seperate liquids due to their diffrent boiling points
• Ancient greeks:

  Thought matter to be made of indivisible particles
• JJ thompson:

  Created the plum pudding model
• Earnest Rutherford:

  Discovered the nucleus was small and positively charged

  Finding that alpha particles went straight though a gold leaf.
• Neil's bour:

  Deducted that electons exist in shells
• James chadwick:

  Determined that the nucleus must contain nuetons as well as protons
• Proton

  relative charge 1

  Relative mass 1
• Neutron

  Relative charge 0

  Relative mass 1
• Electron

  Relative charge -1

  Relative mass 0
• Mass number:

  Number of protons and neutrons in a nucleus

  (Top number)
• Atomic number:

  Number of protons in a nucleus

  (Bottom number)
• Isotopes:

  Same element

  Diffrent number of neutrons
• Elements were initially ordered according to atomic weight

  Even though they were group together due to simular properties
• Dimittri mendeleev:

  Made more sense to swap or reverse the order of some elements

  The table had gaps in for predictions for elements not discovered
• Electrons shells full up in the order

  2 , 8 , 8 , 2
• Transition metals:

  can donate different numbers of electrons
• Group

  Number of electrons in the outer shell
• Metals

  Donates electrons to gain a full outer shell
• Non metals

  Accepts electrons to gain a full outer shell

  Can form negative ions

  Shares electrons
• Group 1

  Alkali metals

  Reacts with water to produce an alkali
• Group 7

  Halogens

  Forms (1)- ions accepts one electron to gain a full outer shell
• The Nobel gasses

  Group 0-8

  Very unreactive as they have an empty outershell
• Metallic bonding

  This is how metal atoms bond to each other

  They form and lattice of ions

  Surrounded by a sea of delocalised electrons

  Electrons are free to move

  Metals are good conductors of electricity and heat
• Giant covalent bonds

  High melting points

  You would have to break the bonds
• Alloys

  Mixture of metals

  Diffrent size atoms

  Cannot slide over each other

  Hard to break
• Allotropes:

  Structures made of the same elements but arranged differently
• Diamond

  One of the hardest due to strong bonds
• Graphite:

  Delocalised electrons

  Weak bonds

  Conducts electricity as electrons move layers can slide

  Graphene: one layer
• Fullerenes/nanotubes

  used for electronics, composites and medical purposes
• Ionic bonding

  How metals bond to non metals

  Metal atoms donate electrons to non metals to form ions
• Ions are arranged in a lattice repeating negative and postive ions

  Forming a crystal
• Ionic structures have high melting and boiling points due to strong ionic bonds