Reactivity of Metals
Ever wondered why some metals rust quickly whilst others stay shiny for years? It's all about reactivity - how eager metal atoms are to form positive ions when they react.
Metal oxides form when metals react with oxygen in oxidation reactions. Reactive metals like magnesium burn brilliantly in oxygen, whilst less reactive ones like iron just slowly tarnish without flames.
The reactivity series ranks metals from most to least reactive: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, tin, copper. Remember it with: "Please Stop Calling My Aunty Zebra In The Class." Metals above hydrogen react with acids producing hydrogen gas - the more reactive, the more vigorous the fizzing.
Displacement reactions happen when a more reactive metal kicks out a less reactive one from its compound. Pop some magnesium into copper sulphate solution and watch the copper form as the magnesium takes its place. Try copper in zinc sulphate though, and nothing happens - copper isn't reactive enough to displace zinc.
Key Point: Only metals above hydrogen in the reactivity series will react with acids to produce hydrogen gas.
