Which of the following metals form an amalgam with other metals?
(1) Lead
(2) Tin
(3) Zinc
(4) Mercury
Answer: (4) An amalgam is a substance formed by the reaction of mercury with another metal. Almost all metals can form amalgams with mercury, the notable exception being iron. Silver-mercury amalgams are important in dentistry, and gold-mercury amalgam is used in the extraction of gold from ore. Dentistry has used alloys of mercury with metals such as silver, copper, indium, tin, and zinc. Amalgam is an “excellent and versatile restorative material” and is used in dentistry for a number of reasons.
