What is the difference between the mixture of aluminium and iodine and the compound?

Answer 1

The difference between chemical compounds and simple mixtures is that chemical compounds feature two or more atoms that are chemically bonded together. The elements in the chemical compound cannot be separated by "non-chemical" means; physicalmethods won't separate them. Mixtures can be separated without using chemical methods. Let's look at an example with iron and iodine. If we mix iron and iodine, the iron can be "sorted out" from the iodine with a magnet. The magnetic iron particles will be attracted to the magnet, and the iodine will not. That's because the two elements are not bonded together in the mixture; they're just "mixed" together. In the compound iron iodide, however, the iron atoms are bonded to iodine atoms. A magnet cannot be used to separate the two substances in the chemical compound we know as iron iodide. Only a chemical reaction can divide the molecules into their elemental constituents.

Answer 2

A compound (aluminium iodide) is formed from chemical elements, associated by chemical bonding.
A compound is a simple substance, a mixture (Al + I) is formed from two elements, only mechanically mixed, without chemical bonding.
A mixture can be separated by physical procedures, a compound not.