Suggest a suitable method to separate the components of a mixture of iodine and common salt. Explain the principle behind your chosen method.

The most suitable method to separate a mixture of iodine and common salt is sublimation. Iodine is a substance that sublimes, meaning it changes directly from a solid to a gaseous state upon heating without passing through the liquid phase. Common salt (sodium chloride) does not sublime. 

When the mixture is heated, iodine will vaporize and can be collected by cooling the vapors, while the common salt will remain behind in the solid state.