Chemistry Paper 1

• atom is a very small thing
• element is a single type of atom found on the periodic table
• compound is 2 or more elements that are chemically bonded together
• mixture is a compound made up of two or more chemical components that are not chemically linked
• protons:

  • found in the nucleus
  • mass: 1
  • charge: +1
• neutrons:

  • found in the nucleus
  • mass: 1
  • charge: 0
• electrons:

  • found in the outer shell
  • mass 1/2000
  • charge: -1
• top and smallest number is the atomic number, the number of protons in the nucleus
• mass number is the largest and is protons + neutrons
• neutrons= mass number - atomic number
• carbon dioxide is CO2
• Water is H2O
• oxygen gas is O2
• Hydrogen gas is H2
• Nitrogen gas is N2
• Ammonia is NH3
• Hydrochloric acid is HCI
• Sulphuric acid is H2S04
• ways to separate mixtures:

  • distillation
  • evaporation
  • filtration
  • fractional distillation
• distillation is separating things by boiling point
• evaporation is removing liquid to leave the solids which have been dissolved in the liquid in the dish
• filtration is large particles of solid in a liquid are filtered out by a filter paper
• fractional distillation is used to separate a mixture of liquids into two or more liquids based on boiling point
• the plumb pudding model is a cloud of positive charge with negative electrons embedded within it
• the plumb pudding model was discovered by JJ Thompson in 1904
• Neil’s Bohr founded the nuclear model which we currently use
• Rutherford founded the nucleus and protons
• chadwick founded neutrons
• group number tells us the number of electrons in its outer shell
• periods are across and tell us the number of shells
• 1st shell = 2

  2nd shell = 8

  3rd shell = 8
• metals lose electrons to become positive
• non metals gain electron to become negative
• group 1 is called alkali metals
• group 2 is called alkali earth metals
• group 7 is called halogens
• group 8 is called the noble gasses
• group 3-6 is called the transition metals
• the first attempt at a periodic table was by newland in 1800s
• mendeleeves periodic table:

  • by mass
  • left gaps
  • similar patterns
  • predicted properties