Cereal and many different types of metals
Fe2O3
The millions of compounds that exist are made from approximately 115 elements!
This is a tough question to answer due to my lack of knowledge about future materials. The scientists and engineers of the future may very well procure a material that's stronger, cheaper, and more efficiently made than iron and all of its variants, thus making large scale use of iron obsolete. There's no way to know to know whether such a material can be made yet. However, even if the use of Iron is eliminated in large construction projects, I see no reason for why we wouldn't use it. Iron rendered materials such as wood and stone obsolete for large building projects, but that doesn't mean we stopped using wood and stone. I believe that in a theoretical future world, where there is a super-strong material that has knocked down the hegemony of iron, iron will still find a niche to slip into. (additional answer) Also remember that in addition to its strength, iron, or various alloys of iron, are also very useful for making magnets. Iron is also an essential nutrient which performs a role in the transport of oxygen in the body. Even if iron were to become obsolete for all other uses, we would still need to have a certain amount of it in our diets. So I would say that iron will be used in the future, at least as long as the human race continues to exist.
When iron is a liquid, it does not. Solid iron, however, does.
pig iron, wrought iron and cast iron. These are broad classifications used commercially, they can be subclassified. Chemically we say that its pure or impure, contains sulphur/phosphorous/impurities(slag, etc.)/carbon in so and so % range
yes
First, this would be an compound, not an element. Second, it does not exist. If it did exist it would be iron VI oxide, but iron cannot reach such a high oxidation state. However, there is Fe2O3, which is iron III oxide.
Fe3+ N3- . Note this is compound does not exist. iron nitrides are insoluble solids with metallic properties.
Calcium exist only in some iron alloys as an insignificant impurity.
"Ferrous" is a word that means "iron". A ferrous metal is a metal that is derived from iron or is an iron alloy, and cannot exist without being bonded to iron. Magnesium is its own chemical element, and does not include elements of iron innately. It can exist independently of iron molecules, so it is called "non-ferrous".
A magnet is a piece of iron or other material that attracts other iron-containing objects. The characteristic that exists in magnets that does not exist in materials that lack magnetism is the alignment of domains.
Iron(I) doesn't exist.
This oxide doesn't exist.
magic and stuff
The world would not exist. Many of the essential organs in all organisms require iron to function. Therefore human would cease to exist.
Fe2O3
Doesn't exist iron stones are not in Pokemon xd gale of darkness.