Elements, mixtures and compounds

• Element


  A substance that cannot be broken up into simpler substances by chemical means
• Robert Boyle


  • The "father of chemistry" is credited with the definition of an element
  • He was an Irish scientist from Lismore, Co. Waterford
• Today there are over 100 different elements discovered
• Elements have symbols to shorten them, usually the first letter of the element
• Compound


  A substance that is made up of two or more different elements combined together chemically
• Compound examples


  • MgO
  • HO
  • HO
  • Feß
• How to make a compound

  Place the two or more elements together and apply heat so that they chemically combine
• Chemical reaction


  A change that results in the formation of one or more new substances
• Iron and sulfur experiment


  Proves the difference between mixtures and compounds
• Compounds


  • The properties of compounds are different to the properties of the elements that make up the compound
• Compound properties


  • H₂O: Hydrogen-An explosive gas, Oxygen-A highly flammable gas, Water-A liquid that helps put out fires
  • CO₂: Carbon-A black sooty solid, Oxygen-A highly flammable gas, Carbon dioxide-A gas that puts out fires
• Mixture


  Two or more different substances mingled with each other but not chemically combined
• Mixture examples


  • Air, sea water, crude oil, earth and petrol
• Mixtures are easy to separate
• Mixture


  The properties of a mixture are similar to those of the elements in the mixture
• Compound


  The properties of the compound are different to the elements that make up the compound
• Mixture


  It is usually easy to separate the elements in a mixture
• Compound

  It is very difficult to separate out the elements in a compound