Question

why should a magnesium ribbon be cleaned before burning in air
​

Answer 1

Answer:

because when left alone magnesium develops a layer of magnesium oxide which is unreactive so,it must ne cleaned before burning.

Answer 2

Answer:

Due to exposure to air, magnesium reacts and oxide of Magnesium is deposited on the ribbon. The ribbon must be cleaned to effective burn it.

Explanation:

Magnesium is in the second group of the periodic table. It has 2 electrons in the outmost shell making it very reactive. When exposed to air, magnesium reacts with the oxygen in the air and forms oxide of magnesium - Magnesium Oxide which deposits on the ribbon. To effectively burn the ribbon, it has to be cleaned