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.

Answer:

He could physically change the metal by hammering it into a different shape and by melting it; both changes leave it as the same metal. He could chemically change it by reacting a small sample with acid and by exposing it to air to see whether it oxidizes. The observed changes and reaction products could help identify the metal.