Question

1.
Why should a magnesium ribbon be cleaned before burnin​

Answer 1

Answer:

Because it is covered with layer of magnesium oxide so it should be rubbed before burning

Explanation:

Answer 2

Magnesium is a highly reactive metal.

Magnesium ribbon must be cleaned before burning in air so that the layer of magnesium oxide which is formed due to reaction of magnesium with air can be removed in order to increase the rate of the reaction.

it is cleaned with a sand paper.

hope it helps @_@