Aluminum vs Magnesium
Magnesium and aluminum are commonly used elements in the periodic table. Both are naturally occurring metals which are in mineral forms.
Magnesium is the 12th element in the periodic table. It is in the alkaline earth metal group, and in the 3rd period. Magnesium is depicted as Mg. Magnesium is one of the most abundant molecules in the earth. It is an essential element in macro level for plants and animals. Magnesium has the electron configuration of 1s2 2s2 2p6 3s2. Since there are two electrons in the outer most orbital, magnesium likes to donate that electron to another more electronegative atom and form a +2 charge ion. The atomic weight of Mg is about 24 g mol-1, and it is light weighted, but a strong metal. Mg is a crystalline solid with a silvery color. But it is highly reactive with oxygen, thus forms a magnesium oxide layer, which is dark in color. This MgO layer acts as a protective layer. So naturally Mg is not found as a pure element. When free Mg is burnt, it gives a characteristic sparkling white flame. Mg is also highly soluble in water, and reacts with water, at room temperature, releasing hydrogen gas bubbles. Magnesium also reacts well with most acids and produces MgCl2 and H2 gas. Mg is largely found in seawater and minerals like dolomite, magnesite, carnallite, talc, etc. Magnesium is extracted from sea water by adding calcium hydroxide. The resulting magnesium hydroxide precipitate can be filtered out, and it is then reacted with HCl to produce MgCl2 again. By electrolysis of magnesium chloride, Mg can be separated at the cathode. Mg is used in organic reactions (Grignard reagent), and in many other laboratory reactions. Moreover, Mg compounds are incorporated into food, fertilizers and culture media, since it is an essential element for growth and development of organisms.
Aluminum or Al is an element in the group 3 and period 3, and has the atomic number of 13. The electron configuration of Al is 1s2 2s2 2p6 3s2 3p1. Al is a silvery white solid, and it is the most abundant metal in the earth crust. Al is not soluble in water at room temperature. Atomic weight of Al is about 27 g mol-1, and it is a light weighted, durable metal. Al doesn’t easily ignite. Since Al is too reactive to stay in its free form, naturally it occurs in minerals. Main Al containing mineral is bauxite. Large bauxite ores are located in Australia, Brazil, Jamaica and Guinea. It is also in the minerals such as cryolite, beryl, garnet, etc. Due to its low density and resistance to corrosion, Al is largely used in automobiles and other vehicles manufacturing, construction, paints, for household items, packaging etc.
What is the difference between Magnesium and aluminum?
• Aluminum has one electron more than Mg, and the outer electron is in a 3p orbital.
• Aluminum forms +3 cations, whereas Mg forms +2 cations.
• Mg is soluble in water at room temperature, but Al is not.
• Al does not burn easily as Mg does.
• Aluminum is corrosion resistant, but magnesium is not. It needs a protective layer to stop corrosion.