Which one of the following alloys contains a non-metal as one of its constituent ?

An alloy is a substance formed by the combination of two or more elements, where at least one is a metal. While many alloys consist only of metals, some incorporate non-metals to enhance specific properties.

• Steel (Option D): It is primarily an alloy of Iron (a metal) and Carbon (a non-metal). The addition of carbon (typically 0.02% to 2.1% by weight) significantly increases the strength and hardness of iron.
• Brass: It is an alloy consisting of Copper and Zinc, both of which are metals.
• Bronze: It is an alloy primarily composed of Copper and Tin, both of which are metals.
• Amalgam: This is a specific type of alloy formed by Mercury (a liquid metal) with other metals like silver, tin, or gold.

Since Carbon is a non-metal, Steel is the correct answer.