Chemistry Revision "Elements, Compounds and Mixtures"

• Element

  All of the atoms are the same
• Elements

  • Magnesium
  • Sulfur
• Symbol

  Starts with a capital letter
• Compound


  Contains two or more different elements chemically combined in fixed proportions
• Compounds usually have totally different properties to the elements they are made from</b>
• Mixture


  Contains different elements or compounds, but they are not chemically combined
• Mixture

  • Magnesium atoms
  • Sulfur atoms
  • Magnesium sulfide
• Separation techniques for mixtures

  • Filtration
  • Distillation
  • Crystallization
  • Chromatography
• Molecule


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


  • Methane
  • Water
  • Ammonia
  • Chlorine
  • Oxygen
• Molecules that are not compounds contain the same element chemically combined
• A compound is made up of two or more elements chemically combined together.
• Compound names are formed by combining the first part of the name of one element with the second part of another element's name.
• The symbol for an ionic compound is always written as a single word without spaces between the symbols.