2.  An Element is a simple substance that cannot be split up into simpler substances by chemical means

3.  Copper  Aluminium  Silver  Mercury  oxygen

4.  A list of elements written down with symbols.

5.  Names are very long so we use symbols.  Symbols form an international language for scientists.

18. A compound is a substance that is made up of two or more elements chemically combined together

21.  H2(Hydrogen)  Colourless, Oderless, explosive gas  O2(Oxygen)  Colourless, Oderless, tastless gas.  H2O(water)  Colourless liquid  Does not burn

22.  Mg(magnesium)  O2(oxygen)  MgO(magnesium oxide)

23.  Fe(iron)  S(sulfur)  FeS(iron sulphide)

25.  Water is a compound.  Its simbol is H 2 O  There are always 2 elements of Hydrogen and 1 element of Oxygen present in H 2 O.

26.  C0 2 Carbon Dioxide  How many elements of Carbon?  How many elements of Oxygen?

27.  In Compounds, elements are always present in fixed ratios.

29.  A mixture consists of two or more different substances mingled with each other but not chemically combined

30.  Is made up of a mixture of mostly Oxygen, Nitrogen, Carbon Dioxide

31.  Air  Sea water  Earth  Crude Oil

32.  Substances in a mixture can be present in any amounts.

33.  No chemical reaction occurs in the making of a mixture.

34.  The properties of a mixture are similar to those of the substances in the mixture.

35.  To make a mixture of Iron and Sulphur and then change the mixture into the compound iron sulphide.

36.  Mix 7g of Iron filings and 4g sulphur.

37.  Test with a magnet.

38.  Heat in a test tube

39.  Examine the compound created.  This is iron sulphide.

40.  It is a compound of the 2 elements iron and sulfer  Iron sulphide has a new appearance and properties of its own.

41.  When elements combine to form compounds the elements lose their individual properties.

42.  Mixture  Amounts of each element not fixed  Contains 2 or more substances  Has same properties as the substances that make it up.  No chemical reaction occurs  Easy to seperate

43.  Mixture  Amounts of each element not fixed  Contains 2 or more substances  Has same properties as the substances that make it up.  No chemical reaction occurs  Easy to seperate  Compounds  Elements are present in same amounts always  Is a single substance  Different properties to the origional elements  Chemical reaction occurs  Difficuilt to seperate