topic c1- atomic structure + the periodic table

• atoms have

  • protons in the nucleus
  • neutrons in the nucleus
  • electrons orbiting the nucleus
• electron- mass

  very small
• electron charge

  -1
• neutron mass

  1
• neutron charge

  0
• proton mass

  1
• proton charge 


  +1
• the number above the element is the

  mass number
• the number below the element is the

  atomic number
• atomic number=

  number of protons
• number of protons=

  number of electrons
• atoms-neutral

  charges cancel out
• mass number

  sum of number of protons and neutrons
• isotope

  • protons stay the same
  • a change in the number of neutrons
• ion

  • protons stay the same
  • a change in the number of electrons
• compound

  two or more substances chemically bonded together
• mixture

  two or more substances mixed together that are NOT chemically bonded
• separating methods

  • evaporation/ crystallisation
  • filtration
  • chromatography
  • distillation
• evaporation/ crystallisation

  • heat solution
  • some solvent evaporates
  • once crystals form, remove the heat
  • dry the crystals out
• filtration

  • removes insoluble solids from a liquid
• chromatography 


  • separates compounds from a mixture
• simple distillation

  separates mixtures

  • with heat and could be seawater
• fractional distillation

  • separates multiple mixtures
• plum pudding model

  • solid spheres of positive charge
  • with small negative charges floating within
  • later to be named electrons
• nuclear model

  • positive nucleus in the centre
  • electrons orbit
  • 2, 8, 8, 2 electron structure
  • lots of empty space
• group 1 elements

  alkali metals
• alkali metals

  • lithium
  • sodium
  • potassium
• properties of alkali metals

  • very reactive
  • 1 electron in outer shell
  • form ionic compounds
  • soft to touch
• group 7 elements

  halogens
• halogens

  • fluorine
  • chlorine
  • bromine
• properties of halogens

  • very reactive
  • 7 electrons in outer shell
  • coloured vapour non metals
• group 8 elements (0)

  noble gases
• noble gases

  • helium
  • neon
  • argon
• properties of noble gases

  • inert/ unreactive
  • full outer shell
  • colourless gases
  • non flammable
• elements

  a substance made from only one type of atom