Which one of the following materials does not actually contain any silver, even though its name suggests otherwise?

Introduction / Context:
This question tests your basic chemistry awareness and your ability to look beyond names. Many chemical substances and alloys have traditional names that suggest a certain element, but sometimes that element is not present at all. Here, you need to find which so called silver compound or material does not contain the metal silver.

Given Data / Assumptions:

• Four names are given: Horn silver, Ruby silver, Lunar caustic, and German silver.
• At least three of these are known silver compounds.
• One is an alloy that does not contain elemental silver.

Concept / Approach:
The key is to recall the common chemical identities behind these names. Horn silver, Ruby silver, and Lunar caustic are historical names for specific silver compounds. German silver, despite its name, is an alloy that does not include silver and is named for its appearance.

Step-by-Step Solution:
Step 1: Horn silver is the old name for silver chloride, a compound of silver and chlorine, so it definitely contains silver.Step 2: Ruby silver refers to complex silver antimony or silver arsenic sulfides, again containing silver in their structure.Step 3: Lunar caustic is the old name for silver nitrate, a compound of silver, nitrogen, and oxygen, also containing silver.Step 4: German silver, despite its name, is an alloy mainly of copper, zinc, and nickel, with no silver content. It looks silvery in colour, which explains the misleading name.Step 5: Therefore, the material that does not contain any silver is German silver.

Verification / Alternative check:
Chemistry reference books list German silver as nickel silver or new silver, describing it as an alloy with a silvery appearance but explicitly stating that it does not contain silver. The other three terms are repeatedly listed among classical silver compounds.

Why Other Options Are Wrong:
Horn silver: This is silver chloride, which clearly contains silver ions.Ruby silver: This name is used for minerals like proustite and pyrargyrite, which are sulfides of silver and antimony or arsenic.Lunar caustic: This is silver nitrate, a widely used laboratory chemical that includes silver.

Common Pitfalls:
Some candidates may be tempted by Lunar caustic because the name does not explicitly include the word silver, but it is a well known silver salt.Another pitfall is to assume that because German silver has a national label in its name, it must be a real silver alloy used for coins, which is incorrect.

Final Answer:
The only material listed that does not contain silver is German silver.