Metals+reacting+with+Oxygen

Remember the **magnesium** strip burning with the bright light? Here is the extreme version of the reaction:

Magnesium metal (Mg) burning in oxygen:

media type="file" key="Magnesium Flare.mov" width="300" height="300"

Oxygen is a very reactive substance and some metals, like aluminium (Al) and sodium (Na), react rapidly with oxygen. In a few seconds surfaces of these metals become dull as **layer of metal oxide** form:

aluminium + oxygen -> aluminium oxide sodium + oxygen -> sodium oxide

These dull oxide layers, or coatings can be removed by polishing or sanding.

__Here are some questions you should think about:__


 * //Q. A lump of sodium metal appear to be white (on its surface). Suggest a reason for this.//**


 * //Q: Magnesium ribbon used in school labs is expensive. Suggest how it should be stored in the lab so that it does not turn into magnesium oxide.//**