1. Pure element - only one type of atom present2. Mixture of two elements - two types of uncombined atoms present3. Pure compound - only one type of compound present4. Mixture of two compounds - two types of compounds present5. Mixture of a compound and an element - one compound and one element presentTwo or more elements or compounds NOT chemically combined. Mixture can be uniform (called homogeneous) and are known as solution. Mixture can also be non-uniform (called heterogeneous).