atomic structure and the periodic table

• Element

  substance made up of only one type of atom
• Compound


  Two or more different elements chemically combined in fixed proportions
• Mixture


  Different elements or compounds, not chemically combined
• Separation techniques for mixtures

  • Filtration
  • Distillation
  • Crystallization
  • Chromatography
• Molecule


  Any elements chemically combined, even if they are the same element