Chemistry - Chemical Reactions of Metals

In your Chemistry lessons you will have looked at the periodic table. The majority of chemical elements on the periodic table are metals. They are arranged in groups that have similar chemical properties. Some of the metals are highly reactive; you have probably seen the video of the reaction between caesium and water - BOOM! But luckily for us, not all metals have quite so violent reactions and they don't explode when in contact with water!

Steel (apart from stainless steel and a few other special steel alloys) is a metal that reacts chemically with water, but only when oxygen is present. That is because it is made from iron which is a moderately reactive element. Steel therefore needs to be protected from contact with water by coating it with things like paint or plastic.

Many metals react with strong acids like hydrochloric, sulfuric and nitric acids. You will have seen this many times in the school laboratory. The more reactive ones effervesce (fizz) and, as they dissolve, the acid gets hotter because it is an exothermic chemical reaction. With weaker acids like citric acid or vinegar, the reaction is much slower and less heat is released. There are some metals that don't seem to react with acids at all - gold and silver for example.

You will also have seen in your Chemistry lessons that many metals will burn - magnesium is probably the one that you think of first. If the metal is ground up into a fine powder or made into thin wires, even the common metals you meet like iron and aluminum will also burn.

The chemical reactions of metals often influence how they are used. Jewelry is made from gold, silver and platinum because they are unreactive and will stay nice and shiny. Aluminum reacts quickly with oxygen in the atmosphere forming an aluminum oxide layer on the surface. This is impermeable and protects the aluminum from corroding any further. This particular chemical reaction is very useful as it means that we can use aluminum for things like greenhouse frames and door frames.