Which among the following alloys contain mercury as one of its constituents? A Stainless steel  B Alnico  C Solder  D Zinc amalgam

To determine which among the given alloys contains mercury as one of its constituents, we need to analyze each option:

A) Stainless steel: Stainless steel is primarily composed of iron, chromium, and nickel. It does not contain mercury.

B) Alnico: Alnico is a type of magnet alloy composed of aluminum, nickel, and cobalt. It does not contain mercury.

C) Solder: Solder is a metal alloy used for joining or bonding other metals together. While there are different types of solder, the most common one is a mixture of tin and lead. It does not contain mercury.

D) Zinc amalgam: An amalgam is a mixture of mercury with another metal. In this case, zinc amalgam contains mercury as one of its constituents.

Therefore, the correct answer is option D) Zinc amalgam.