Classification – Odd one out (alloys vs element): Identify the outlier: Brass, Gun metal, Bronze, Germanium.

Introduction / Context:
Materials science distinguishes alloys from pure elements. Three items are copper-based alloys; one is a semiconductor element from the periodic table.

Given Data / Assumptions:

• Brass → alloy (copper + zinc).
• Gun metal → alloy (typically copper + tin + zinc).
• Bronze → alloy (copper + tin, variants exist).
• Germanium → element (Ge), semiconductor.

Concept / Approach:
Decide if each is a mixture (alloy) or single element. The sole element is the outlier.

Step-by-Step Solution:
Brass/Gun metal/Bronze → alloys.Germanium → element.

Verification / Alternative check:
Chemical symbols exist only for elements; “Ge” confirms Germanium’s elemental status.

Why Other Options Are Wrong:

• Brass, Gun metal, Bronze are mixtures with variable compositions.

Common Pitfalls:
Assuming “metal” equals “element.” Many common “metals” are industrial alloys.

Final Answer:
Germanium