Reactivity and Metals
Ever wondered why gold jewellery stays beautiful for centuries whilst iron gates rust in months? It's all about metal reactivity - how eagerly different metals react with other substances.
The reactivity series ranks metals from most to least reactive. At the top, you've got potassium, sodium, and lithium - these are so reactive they can explode when they touch water! Moving down, calcium and magnesium react quickly but less violently. Zinc and iron sit in the middle, reacting slowly with acids. At the bottom, copper and gold barely react at all, which is why they're perfect for coins and jewellery.
You can test reactivity by watching how metals react with cold water or dilute acids. The more reactive metals fizz violently and release hydrogen gas bubbles. Less reactive metals like zinc react slowly, whilst copper and gold don't react at all.
Displacement reactions happen when a more reactive metal kicks out a less reactive one from a compound. For example, if you put magnesium into copper sulfate solution, the magnesium displaces the copper, leaving you with pure copper metal and magnesium sulfate solution.
Key Tip: Remember "Please Stop Calling Me A Careless Zebra, Instead Try Learning How Copper Saves Gold" to memorise the reactivity series from most to least reactive!