1. Magnesium ribbon burnt in air

 

 

When a magnesium ribbon is burnt in air, it reacts with carbon dioxidereacts with nitrogenreacts with oxygenreacts with hydrogen present in the air and forms a new substance called magnesium sulphatemagnesium chloridemagnesium oxidemagnesium sulphide. Magnesium oxide is obtained as a brown powderblack powderblue powderwhite powder. During this reaction, only sound is producedonly smoke is producedheat and light are also producedonly heat is produced. Since a new substance is formed, the burning of magnesium ribbon is a reversible changechemical changephysical changetemporary change. This reaction is an example of condensationevaporationcombustionmelting, in which a substance reacts with oxygen to produce heat and/or light.