Burning of magnesium ribbon is an example of which change?

Correct answer: Chemical change

The governing concept is that a chemical change forms one or more new substances with properties different from those of the original material. When magnesium burns in oxygen, it undergoes the reaction 2Mg + O₂ → 2MgO. Magnesium oxide is a new compound, so the chemical identity of the starting magnesium changes. The brilliant white light and white solid residue are observable evidence, although the formation of magnesium oxide is the decisive reason for classification. Therefore option B is correct. The process is not merely compression, because no squeezing explains the new compound, and it is not only melting, because melting changes state without changing composition. Option A is therefore also incorrect.