Identifying Copper-Free Alloys

An alloy is a mixture of two or more elements, where at least one element is a metal, and the resulting material has metallic properties.

The question asks to identify which of the given options is a copper-free alloy. Let's examine the composition of each alloy mentioned:

• German silver: This is an alloy primarily composed of copper, zinc, and nickel. Despite its name, it contains no silver but has a silvery appearance. Its typical composition includes copper (around 50-60%), zinc (around 15-30%), and nickel (around 10-30%). Since it contains copper, it is not copper-free.
• Muntz metal: This is a type of alpha-beta brass, which is an alloy of copper and zinc. It typically contains about 60% copper and 40% zinc. It is used in marine applications due to its corrosion resistance. Since it contains copper, it is not copper-free.
• Gun metal: This is a type of bronze, which is an alloy of copper, tin, and often zinc. A common composition is around 88% copper, 10% tin, and 2% zinc. It is known for its strength and corrosion resistance. Since it contains copper, it is not copper-free.
• White metal: This is a broad term used for various alloys with a light color. Common types of white metal include alloys based on tin, lead, zinc, or antimony, often used as bearing materials (like Babbitt metal) or for casting decorative items. While some specific formulations might include trace amounts of copper, they are generally considered copper-free or contain copper in negligible amounts compared to the other listed alloys, which are primarily copper-based. For the purpose of this question, among the given options, White metal is the one that is essentially copper-free.

Based on the primary compositions of these alloys, White metal is the alloy that is copper-free among the given options.