why does aluminum not rust?
607505
Aluminum DOES rust; it just isn't like iron rust. Aluminum oxide (chemical formula Al2O3) forms a thin film on the outside of the aluminum. \n\nSome people say, figuratively, that we have never really seen aluminum, because the oxide coating forms so quickly; (I have to disagree with what someone else wrote above) you can't scratch aluminum and then see the true color before the oxide covers it.\n\nAl2O3 is chemically the same as sapphire, it is very hard and strong. Once the coating has formed on the surface, it protects the rest of the aluminum in the bulk of the piece, so it doesnt corrode away. The coating is very thin, though-- only one molecule thick-- so we don't notice it and it doesn't really add any structural strength to the aluminum. \n\nBy contrast, iron rust is very weak. It crumbles and falls apart very easily; it can't even support its own weight. So it breaks off the surface of the iron and leaves fresh iron exposed to rust. That is why bridges and girders fall alart if they are not painted or protected from the elements. But aluminum protects itself.
890588
Ferrous metals (iron/steel) rust and non-ferrous (aluminum/copper) metals oxidize.\nBoth are chemical reactions and effects of oxygen and moisture present in the atmosphere.\nBTW, ferrous metals are magnetic, non-ferrous metals aren't. Try it.
41970
ya, rusting is called "oxidation" because the iron reacts with the oxygen in the air to produce iron oxide:  Fe + O2 -> Fe2O3  iron oxide = rust.\n\nanyway, if you coat the iron with a film of something, the air can't get to the iron and voila, no rust!  this is also why things that rust are painted - paint does the same thing.\n\ni'm not sure how to answer the 2nd part of your question - doesn' make sense and to be honest, just doesn't jive with my experiences.  sorry!
945874
Galvanised Pipe will not make rust.
149897
Depends on the temperature. At a guess at melting point not that different from solid aluminum.
1094317
aluminium because its an alkali earh metal and\nfluorine is a halogen
150659
You may be referring to a sacrificial anode?\n\nSometimes, in order to prevent something from rusting (like a metal water pipe or the hull of a ship), you sacrifice a more reactive metal to corrode first.\nFor example, if you wanted to protect an Iron water pipe from rusting, you could electrically conect it to a "sacrifical" piece of Magnesium (a more reactive metal)m this way, the Mg will corrose first, keeping the Iron safe.\n\nEdit:\nYou wouldnt mix the sacrifical metal in with the metal your trying to protect, then you'll just get an object with a bunch of holes in it (where the other metal was eaten away).  You would electrically connect the sacrifical electrode to the other metal with a wire or something of that sort, then as the sacrificial electrode is corroded away, the other metal stays perfectly intact.\nI think in real life Magnesium is a very common metal to use since it is so high up in the reactivity series and not insanely expensive. Silver doesnt corrose very much at all, it wouldnt work as a sacrifical electrode, not would it need one very badly.
940458
Of the ones you listed Aluminum would be the best mostly because it is a metal.
723440
mild steels will almost allways be corroded by HCl and H2SO4.  Depending on the pH and electric potential conditions different oxides and other iron ions will form, but it is very difficult to prevent the corrosion.  in addition, the oxides that will for are generally not adherent meaning they will not stick to the surface and protect the metal.\n\nthe bottom line is except for very rare conditions the steel will corrode and will be eventually completley destroyed, and i'm sure you can imagine what this will do to the properties.  to prevent this, just use an appropriate stainless steel alloy
125056
It does rust.  Due to the form it takes, it takes on oxygen molecules, carrying them with the iron for a time until it is released farther into the body.  If your blood's iron was blocked from combining with oxygen, what we call "rusting", you would die from lack of oxygen.
61960
Most dyes and paints will not stick to aluminum. See the website below for information about anodizing aluminum, a process that *will* work.
100074
"rusts" are actually metallic oxides. Ferrous oxide is reddish brown. Zinc oxide is white. Aluminum oxide is whitish gray.
972949
WARNING:  Answer is NOT OXYGEN.\n\nIt is true that when metals rust, it forms metal oxides.  But by definition, Catalyst Speeds up the process of the Rxn but does not get used up.  However as you can see in the equation below, Oxygen is consumed with metal to for metal oxide.  Therefore Oxygen CAN'T be a catalyst.  It is a reactant.\n\nFe + O2 ---> Fe2O3\n\nThe Correct answer is SALT.  (Sodium in NaCl for an example)\n  \nRust is the process of metal oxidizing into metal oxide.  The oxidation needs a transfer medium to occur, such as water. Salt in the water speeds up the oxidation process by acting as a catalyst.  The salt is never used up and the problem with salt is that even when water is gone, it remains and wait to restart the forming of rust once more moisture is present.  This is why metals rust much easily in salty areas such as beaches and cold states where they use salt to melt the icy roads.   \n\nI hope you get my answer in time, if this question if for school.  I know I'm against 3 answers here but let my past records of best answers speak for itself.
364252
Blood does not contain enough iron to rust (rust is FeO2).  Rust is caused by the synthesis reaction:\n\n             Fe  +  O2 -------> FeO2\n\nWithout the right circumstances this will not happen, the right circumstances being that there be enough iron there for the reaction to occur.
1155855
Possibly the material underneath the stainless is corroding and the rust found a way through. It's not necessarily solid stainless steel.
232646
Fire is oxidation of a material at a fast rate. The aluminum foil you put in the stove getx a coat of aluminum oxide on it and then goes no further as a gas oven is not hot enough to "burn" aluminum. Aluminum can be burned if one gets the temperature hot enough. This is called the thermite reaction and happens when finely divided aluminum, such as shavings is mixed with iron oxide (rust) and the mixture set afire with a fuse perhaps made from thin strips of magnesium metal. The iron oxide or rust becomes iron metal again and the aluminum becomes aluminum oxide or alumina. The heat is intense enough to melt iron.Such reactions are used in industry to perform welding. It is all quite dangerous and a person not familiar with the laws of chemistry may become blinded by the light of the reactions involved or harmed by server burns. Do not try this at home.
708657
Vinegar is an acid and is also a catalyst for corrosion of iron\n\nOil is hydrophobic and will prevent oxidation from occurring, therefor preserving the iron\n\nWater will promote oxidation and in turn degrade the iron to iron oxide (rust)