Which of the following is NOT an alloy?
- A.Solder
- B.Silver
- C.Bronze
- D.Brass
Correct answer
Explanation
The correct answer is B, silver. Silver is an element, a pure metal with its own place in the periodic table, so it cannot be an alloy; an alloy is a homogeneous mixture of two or more metals, or of a metal with a non-metal such as carbon. Option A, solder, is an alloy of lead and tin, valued for its low melting point when joining electrical wires. Option C, bronze, is an alloy of copper and tin, the metal that gave its name to an age of human history. Option D, brass, is an alloy of copper and zinc, used for utensils, fittings and musical instruments. The trap here is German silver, which contains copper, zinc and nickel and no silver at all, so it is an alloy despite its name, while silver itself is not.
Read the full article: Metals and Non-Metals: Properties, Ores and Alloys
Practice Questions
View allCalamine is an ore of:
- A.Tin
- B.Magnesium
- C.Zinc
- D.Copper
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Calamine is zinc carbonate, and since it is a carbonate ore it is converted to the oxide by calcination, that is by heating in the absence of air, before being reduced to the metal.
Read the full explanation →Which of the following is the most ductile metal?
- A.Gold
- B.Copper
- C.Silver
- D.Iron
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Ductility is the property of being drawn into a wire, and gold is the most ductile metal known; it is also the most malleable, so a very small quantity can be beaten into an extremely thin sheet or drawn into a very long wire.
Read the full explanation →Brass is an alloy of:
- A.copper and tin
- B.copper and nickel
- C.copper and iron
- D.copper and zinc
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Brass takes the workability of copper and the hardness of zinc, resists corrosion and is easy to cast, which is why it is used for utensils, locks, taps, fittings and wind instruments.
Read the full explanation →Which metal is in the liquid state at room temperature?
- A.Sodium
- B.Mercury
- C.Lead
- D.Tungsten
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Mercury is the only metal that is liquid at ordinary room temperature, which is why it was long used in thermometers and barometers; it is also the metal that forms amalgams, alloys in which mercury is one component.
Read the full explanation →Aqua regia, which dissolves gold, is a mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio:
- A.1:1
- B.1:3
- C.3:1
- D.2:3
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Aqua regia is three parts concentrated hydrochloric acid to one part concentrated nitric acid, and the name means royal water, given because the mixture attacks the noble metals gold and platinum, which neither acid can dissolve on its own.
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