Question

A student while burning a magnesium ribbon

Answer 1

Answer:

magnesium hydroxide as magnesium oxide mixes with the wet watch it turns magnesium hydroxide .

Answer 2

While burning, Mg ribbon turns to MgO2 (Magnesium Oxide). Magnesium Oxide is Basic, odourless, and non toxic, the student can observe a greyish substance collected on the watch glass, if students adds H2O to it, it turns into H2MgO2 (Magnesium Hydroxide).