Question

10. Magnesium ribbon is rubbed before
burning because it has a coating of​

Answer 1

Answer:

MgO (Magnesium oxide)

Explanation:

When Mg ribbon is exposed to air, an oxide layer of Mg forms over it which prevents its further reaction. Thus it is rubbed with sandpaper to remove this oxide layer.

Answer 2

Answer:

we do so , to remove the upper protective layer of magnesium oxide so that magnesium ribbon burns readily