Introduction / Context:
Amalgams are important in chemistry, dentistry and metallurgy. An amalgam is an alloy in which mercury is a major component, and it is capable of dissolving or forming solid solutions with many other metals. Questions about amalgams often appear in general science and chemistry sections of competitive exams, testing whether students know which metal plays the central role in forming these mixtures.
Given Data / Assumptions:
• The question asks which metal forms an amalgam with other metals.
• Options include mercury, zinc, tin and lead.
• We assume knowledge of basic alloys used in science and industry.
Concept / Approach:
By definition, an amalgam is an alloy of mercury with another metal. Mercury can combine with metals such as silver, gold, zinc and copper to form amalgams with various uses. Historically, these amalgams have been used in dental fillings, gold extraction and mirror making. Therefore, the metal that characteristically forms amalgams with other metals is mercury, not zinc, tin or lead individually, even though they can be components of a mercury amalgam.
Step-by-Step Solution:
1. Recall the definition: An amalgam is an alloy of mercury with another metal.
2. Identify the metal that must be present in almost all amalgams.
3. Mercury is liquid at room temperature and can dissolve other metals to form such alloys.
4. Zinc, tin and lead can form alloys, but those alloys are not called amalgams unless mercury is involved.
5. Therefore, the correct answer is the metal that characterizes amalgams: mercury.
Verification / Alternative check:
If you look up examples of amalgams, you will find terms like ‘‘dental amalgam’’ (mercury with silver, tin, copper and other metals) and ‘‘gold amalgam’’ used in mining. In every case, mercury is the key component that combines with the other metal to form the amalgam. No standard chemical reference defines zinc, tin or lead alone as the fundamental amalgam-forming metal. This confirms that mercury is the accurate choice.
Why Other Options Are Wrong:
Option B, ‘‘Zinc’’, is used in some amalgams (for example, zinc amalgam), but without mercury the alloy would not be called an amalgam. Option C, ‘‘Tin’’, is present in dental amalgam, yet tin by itself does not define the term amalgam. Option D, ‘‘Lead’’, also forms alloys with various metals, but these are simply called lead alloys, not amalgams. The defining metal is always mercury, which is why the other options are incomplete or misleading.
Common Pitfalls:
Students sometimes think that any metal mixed with another is an amalgam, confusing amalgams with alloys in general. Another pitfall is focusing on dental or industrial examples where several metals appear together and then incorrectly picking zinc or tin as the main metal. Remember the key concept: the word ‘‘amalgam’’ is reserved for alloys where
mercury is the essential component combined with other metals.
Final Answer:
The metal that forms amalgams with other metals is
mercury.
Discussion & Comments