A laboratory receives a copper-colored metallic sample labeled “X.” The sample’s measured density is essentially identical to that of pure copper, yet its electrical conductivity is significantly lower. A tensile test shows that the sample fractures at a lower strain than pure copper under the same testing conditions.
(a) Based on the observations, infer whether sample X is more likely a substitutional alloy or an interstitial alloy. Provide detailed reasoning.
(b) Suggest one element that could plausibly be the solute in sample X and explain how atomic radius considerations support your choice.
(c) Using the electron-sea model, explain why the observed alloy type would account for the reduced electrical conductivity.
(d) Propose one additional experiment that could be performed to confirm the alloy classification you proposed in part (a), and describe the expected results for each possible alloy type.