Question

describing physical and chemical changes
an industrial chemist is studying a sample of an unknown metal. describe two ways he could change the metal physically and two ways he could change the metal chemically to try to identify it.

Explanation:

Physical changes alter the metal's form without changing its chemical identity, while chemical changes create new substances to reveal the metal's unique chemical properties for identification.

Answer:

Physical changes to identify the metal:

1. Shape/Size Alteration: Cut or bend the metal to test malleability, a physical property unique to some metals.
2. Phase Change: Melt the metal to measure its melting point, a characteristic physical property.

Chemical changes to identify the metal:

1. Acid Reaction: Expose the metal to a dilute acid (e.g., hydrochloric acid) to observe if it produces gas, as different metals react uniquely with acids.
2. Oxidation Test: Expose the metal to air/water over time to observe the type of oxide layer it forms, which is specific to the metal.