The Reactivity Series

• The reactivity series lists metals in order of their reactivity towards other substances

  
• For metals, their reactivity is determined by how easily they lose electrons - forming positive ions. The higher up the reactivity series a metal is, the more easily they form positive ions

  
• The higher a metal is in the reactivity series, the more easily it reacts with water or acid

  
• If you compate the relative reactivity of different metals with either an acid or water and put them in order from most reactive to the least reactive, the order you get is the reactivity series

  
• Carbon and hydrogen are non-metals but are often included in the reactivity series

  
• How metals react with acids tells you about their reactivity
• Some metals react with acids to produce a salt and hydrogen gas:

  acid + metal -> salt + hydrogen
• The speed of reaction is indicated by the rate at which the bubbles of hydrogen are given off
• The more reactive the metal, the faster the reaction will go
• Very reactive metals like potassium, sodium, lithium and calcium react explosively, but less reactive metals such as magnesium, zinc and iron react less violently
• In general, copper won't react with cold, dilute acids
• Magnesium reacts vigorously with cold dilute acids such as HCl(aq) or H2SO4(aq) and produces lots of bubbles

  Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g)

  
• Both zinc and iron react slowly with dilute acids but more strongly if you heat them up

  
• HCl reacts to form chloride salts, H2SO4 reacts to make sulfate salts
• You can also investigate the reactivity of metals by measuring the temperature change of the reaction with an acid or water over a set time period. If you use the same mass and surface area of metal each time, then the more reactive the metal, the greater the temperature should be
• The reactions of metals with water also show the reactivity of metals:

  metal + water -> metal hydroxide + hydrogen

  e.g. Ca(s) + 2H2O(l) -> Ca(OH)2(aq) + H2(g)
• The metals potassium, sodium, lithium and calcium will all react with water
• Less reactive metals like zinc, iron and copper won't react with water