Chemistey question about reactivity of metals

First of all, place a small piece of each of the magnesium, iron and silver in a test tube, and then add zinc sulphate solution to each test tube.

Only magnesium can give a silvery metal of zinc. In other words, only magnesium can displace zinc from a solution zinc sulphate. Therefore, magnesium is more reactive than zinc.

Since iron and silver cannot displace zinc from a solution zinc sulpate, iron and silver are less reactive than zinc.

Reactivity: magnesium > zinc > (iron and silver)

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Then place a small piece of iron in a test tube, and then add silver nitrate solution to the test tube.

A silvery metal of silver is formed and the colourless solution turns pale green. In other words, iron can displace silver from a solution of silver nitrate. Therefore, iron is more reactive than silver.

Reactivity: magnesium > zinc > iron > silver
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