Paperclips Model: The definition for these paperclips is based upon their characteristics. The paperclips can be represented as atoms that break apart and form different mixtures. If a paperclip is one of its own and has no changes, it is just a paperclip without any features, large or small, it is a pure substance. However, if the paperclip has different features, it has became a mixture, and then a compound if there are multiple features.