cotton is decomposable
Yes, everything biological is.
yes it is decomposable and after that it is used to make many important things to be used for human being.
No, but it can be physically reduced to dust.
Eggs are decomposable, so placing eggs with this mind of material will cause it to go bad and decompose. Don't do it.
paper, leaves, tomatoes, any plants
no its not you can look up other metals and fossil fuels that are though:]