Test: Chemical Properties of Metals

Magnesium is more reactive than zinc therefore it can displace zinc from its solution.

During electrolytic decomposition metals are deposited at the cathode because metals upon electrolysis form positive ions and as we know that Cathode is negatively charged it attracts the positive ions and hence metal get deposited on the cathode

Copper metal is more reactive than silver nitrate so it can displace silver and can form copper  nitrate. 

Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Amphoteric oxides include lead oxide and zinc oxide, among many others. 

When Zn reacts with dilute HCl, hydrogen gas is evolved. 
Zn + 2HCl → ZnCl2  + H2
 

The final solution becomes colorless and not light green since aluminum sulphate is colourless.

Al > Zn > Fe > Cu is the decreasing order of metals in reactivity series.

Potassium oxide is an ionic compound formed by combining potassium and oxygen. It is denoted by K₂O. Potassium oxide is a strongly corrosive alkali, which when dissolved in water. 

Heated copper metal reacts with oxygen to form the black copper oxide. The copper oxide can then react with the hydrogen gas to form the copper metal and water.

Nitric acid is a highly oxidising agent. So when metals react with nitric acid and liberate hydrogen, this hydrogen immediately react with water and as a result no hydrogen is evolved out.