Compounds

• a compound is made up of more than one element joined together chemically
• water has two hydrogen atoms bonded to one oxygen atom by covalent bonds
• the formula for water is H2O
• A compound is formed by a metal and a non metal which consists of ions.
• Sodium chloride is an ionic compound because it contains both positive and negative ions held together by electrostatic forces
• When a metal loses an electron it becomes a positive ion.
• When a non metal atom gains an electrons it forms negative ions.


  Compounds
• The opposite charges(positive and negative) of the ions mean they’re strongly attracted to each other.


  What is ionic bonding?
• A compound formed from non metals consists of molecule.Each atom shares an electron with another atom.


  What is covalent bonding?
• sodium chloride,magnesium oxide and calcium oxide.

  What are examples of ionic bonding?
• A formula shows what atoms are in a compound.Compounds are represented by formulas.The formulas are made up of elemental symbols in the same proportions that the elements can be found in the compound.


  What is a formula?
• carbon dioxide is a compound formed by an chemical reaction between carbon and oxygen.It contains one carbon atom and two oxygen atoms.