Elements, compounds and mixtures

• Element

  All of the atoms are the same
• Compound

  Contains two or more different elements chemically combined in fixed proportions
• Compounds usually have totally different properties to the elements that they're made from
• Mixture

  Contains different elements or compounds, but they are not chemically combined
• Separation techniques for mixtures

  • Filtration
  • Distillation
  • Crystallization
  • Chromatography
• Molecule

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