Rusting can be a very quick and powerful reaction. The type of rusting that we are familiar with is slow. Given the right conditions this reaction occurs very fast and gives off a great deal of energy.

Sparklers contain a mixture of metals which include aluminium, iron and magnesium. The mixture also contains oxidants. Oxidants are chemicals that produce oxygen when heated. The heat energy produced speeds up the oxygen molecules and causes them to collide quickly and violently with the metal atoms. The reaction now proceeds very quickly indeed.

Al = aluminium, Fe = Iron, Mg = Magnesium.

1) Draw the following compounds representing the atoms as spheres.

a) aluminium oxide (Al2O3)

b) magnesium oxide (MgO)

c) iron(III) oxide (Fe2O3)

Sparklers are good example of the energy released during rusting reactions. Click to see a120kb movie of a home made sparkler.

2) The following reactions represent the rusting of the different metals in the sparkler mixture. Draw the reactions representing atoms as spheres.

a) 4Fe(s) + 3O2(g) => 2Fe2O3(s)

b) 2Mg(s) + O2(g) => 2MgO(s)

What can you say about the number of each atom at the start and at the finish of the reaction?

3) Look at the video of a spherical sparkler burning and compare it to the video of the sparkler powder burning. Explain the difference in the rate of burning.

Some metals are very reactive. That is they will react violently and quickly in air or in water. Sodium is a very reactive metal which reacts quickly with water to produce hydrogen gas.

Activity - Make your own sparklers.