Question

Magnesium ribbon burns with dazzling flame in the air and changes into a white substance

Answer 1

magnesium ribbon burns with a dazzling white flame and changes into a white powder. This powder is magnesium oxide. It is formed due to the reaction between magnesium and oxygen present in the air.

OR

It happens because when magnesium ribbons burns in presence of air it undergo oxidation reaction to form magnesium oxide. This change proceeds with the evolution of heat and light due to which we see dazzling white flame.

hope this helps you......