Question

What is amalgam?

Answer 1

Hint: It is an alloy.
- A liquid, solid form or in pastel form which is formed through metallic bonding.

Complete step by step solution:
-The amalgam simply gives the meaning a mixture or a blend of few substances. In chemistry we specifically refer to amalgam as those materials that are the alloys of mercury with another metal.
- The amalgam will be in liquid form or solid form or may be in soft gel type consistency depending upon the concentration or content of mercury (Hg) in it.
Almost every metal forms an amalgam like sodium, aluminium, tin etc.
-But the metals in the exceptional list are iron, tungsten, platinum etc.
Amalgam is formed by the metallic bonding of the metal ions. In amalgam the metal ions get attached to the crystal surface through electrostatic force of attraction. The electrons present in the crystal lattice attract the metallic ion and form the amalgam.

Additional Information:
- We generalize the word amalgam as the alloy of Hg, but it is again classified on the basis of the other metals that combine with mercury like:
Zinc amalgam – which is used in Clemmenson reduction process
Sodium amalgam – which is used as a reducing agent in many organic and inorganic reduction reactions
Ti amalgam- which was used for mirror coating during earlier times.

- Alloy of Hg with silver, tin, copper, zinc etc. is highly used in dentistry and hence called as dentistry amalgam. Amalgam is highly used in dentistry since it is easy to use and it is an affordable restorative material. As it is easy to handle and it remains soft for a short span of time, it is easy to manipulate during the treatment and then after some duration only it gets hard.

Note: Even though it is easy for usage, affordable, very versatile but it is highly toxic and the study has suggested to ban the use of amalgam in dentistry. Now for children below 15 years amalgams are not used for the dental treatments. Hg itself is a toxic material, so it’s always better to use alternatives in the place of usage of such toxic chemicals.