Match these items. 1. symbol for copper Cu 2. smallest unit retaining properties of element element 3. C 6H is an example of an mixture 4. symbol for hydrogen organic compound 5. symbol for sulfur atom 6. a primary substance that cannot be divided into separate substances 7. NaCl is an example of an S 8. a physical combination of two or more pure substances compound 9. any chemical combination of elements Fe 10. symbol for iron inorganic compound