Final answer:
The characteristics of copper dissolving in concentrated nitric acid and producing a deep blue solution and a brown gas are examples of chemical changes, where new substances with different properties are formed.
Step-by-step explanation:
When copper metal is heated in concentrated nitric acid, the process exhibits characteristics which are indicative of chemical changes. The dissolution of copper to form a deep blue solution, which is copper(II) nitrate, demonstrates a chemical reaction where the copper undergoes oxidation. Concurrently, the evolution of brown nitrogen dioxide gas indicates the reduction of nitric acid. Given the production of new substances with different chemical properties, this is an eminent example of a chemical change occurring.
Such transformations are not limited to this reaction alone but are observed widely in chemistry. For instance, cooking red meat or the enzymatic browning of bananas also showcases similar chemical change where the original compounds are converted into different substances. These changes are irreversible under normal conditions and are fundamental in demonstrating how chemical reactions follow the principles of conservation of mass and energy.