Note: Magnesium is the eighth most abundant element in the earth’s crust, and about 2% of it makes up the earth. Magnesium is chemically very active. When heated, it changes into many different compounds. Magnesium is used to make many different metals.
Answer: When left open in the air, Magnesium reacts with atmospheric oxygen to form Magnesium Oxide (MgO). The MgO layer does not burn or slow down the burning process, and thus should be removed. So the Magnesium ribbon should be cleaned off with a sandpaper before burning, to remove impurities that may cause a reaction. Once cleaned, only pure Magnesium is present and can react without interference from other substances.
Magnesium is an alkaline Earth metal. Alkaline Earth metals are very reactive because they have just two electrons in their outer electron shell. Besides the fact that it has a high reactivity with oxygen and water, the element has the ability to start fires and cause explosions. This is why magnesium is used for military explosives and missile propellant.
Air composed of nitrogen and oxygen. They are both important components of air. Remember that magnesium only reacts with oxygen in the air to form an oxide coating on its surface but it doesn’t react with the atmospheric nitrogen at all. This is because gaseous nitrogen is really inert and it doesn’t react with magnesium.
The magnesium ribbon is a thin strip of magnesium alloy that produces intense heat and bright white light when it is ignited. It works by burning in the air. The magnesium ribbon’s brightness decreases with time, and can be extinguished by being submerged in cold water.
The magnesium ribbon lights up with a dazzling white flame and changes into a white powder. This powder is magnesium oxide, a new substance that forms from magnesium reacting with oxygen present in the air.