Magnesium ribbon be cleaned before burning in air for the following reason
- The magnesium ribbon which we usually use has a coating of magnesium oxide. Magnesium ribbon reacts with oxygen present in air to form a protective and inert layer of magnesium oxide on its surface.
- This layer is unreactive and prevents the Ribbon from Burning.
- And therefore it needs to be cleaned by rubbing with Sandpaper to remove the protective layer of magnesium oxide from the surface of the magnesium ribbon.
- When magnesium ribbon burns in air it gives dazzling white flame to form a white powder called magnesium oxide. The reason is that when heated magnesium combines with oxygen present in air to form magnesium oxide.