Question

A student burned magnesium ribbon in the lab and observes a white powder falling on the table. what type of reaction has taken place and name the white powder

Answer 1

It is combination reaction. the white powder is magnesium oxide.
$2mg + o2 \: ......... > 2mgo$

Answer 2

When magnesium ribbon is burned in a lab, it reacts vigorously with the oxygen in the air giving out bright flame. This results into the formation of Magnesium oxide.
The white powder is Magnesium oxide.
The reaction that has taken place is combination reaction as Magnesium combines with oxygen.

Balanced Chemical Reaction :-
2Mg + O2 => 2MgO