What is the Difference Between Alloy and Amalgam?

The main difference between an alloy and an amalgam is the composition and the bonding process involved in their formation. Here are the key differences:

1. Composition: An alloy is a homogeneous mixture of two or more metals, or a mixture of a metal and a non-metal. On the other hand, an amalgam is an alloy of a metal with mercury.
2. Formation: Alloys are prepared by taking the desired elements in proper proportion and melting them. Amalgams, on the other hand, are formed through metallic bonding, with the electrostatic attractive force of the conduction electrons working to bind all the elements together.
3. State: Amalgams can exist in different states, such as liquid, soft paste, or solid, depending on the proportion of mercury. Alloys, however, are usually solid substances.
4. Metals: Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum. Alloys can be made from a wide range of metals and non-metals, but they do not involve mercury.

In summary, an alloy is a homogeneous mixture of two or more metals or a mixture of a metal and a non-metal, while an amalgam is an alloy of a metal with mercury. Alloys are formed by melting the desired elements together, whereas amalgams are formed through metallic bonding. Amalgams can exist in different states, whereas alloys are usually solid substances.

Comparative Table: Alloy vs Amalgam

Here is a table comparing the differences between an alloy and an amalgam:

In summary, an alloy is a homogeneous mixture of two or more metals, while an amalgam is a specific type of alloy that always contains mercury as one of its components. Both alloys and amalgams have properties that are different from their individual starting materials.