Elements, Compounds and Mixtures

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Elements, Compounds and Mixtures
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Robert Boyle
An element is a substance which cannot be split
into simpler substances by chemical means
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Examples is Gold, Mercury, Oxygen
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Elements

• 1) Over 100 elements
• 2)Building blocks from which all other materials
  are made from

• 3) Listed on the Periodic Table
• 4) Each element has its own symbol

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• Periodic Table

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Compounds

• 1)Properties of Compounds usually differ
  completely from the elements it is made from
• 2)An example Water which is made up of hydrogen
  and Oxygen.
• Water is a liquid with a refreshing taste, is
  essential to life and does not burn
• Both Hydrogen and Oxygen are colourless,
  odourless, tasteless gases
• Hydrogen is explosive when mixed with air
• And substances burn well in Oxygen

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• 3) In compounds elements are present in a fixed
  ratio.
• Water H2O ......So the ratio is 21. Meaning
  there is two hydrogens for every one oxygen
• The symbol for Carbon dioxide is CO2. Can you
  think of the ratio of the elements in this?

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A mixture consists of two or more different
substances minged with each other but not
chemically combined

• Mixtures

Examples include 1)Air which is a mixture of
gases. 2) Sea water which is a mixture of water,
salt and a number of other substances.