Question

Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?

• A. Brass
• B. Bronze
• C. Amalgam
• D. Steel

Answer 1

The correct option is D

Steel

Alloy: The homogeneous mixture of two or more metals or non-metals to improve their various properties of them, is called an alloy.

For example, aluminium $\left(\mathrm{Al}\right)$ is light but not strong, but an alloy of aluminium with copper $\left(\mathrm{Cu}\right)$, magnesium $\left(\mathrm{Mg}\right)$ and manganese $\left(\mathrm{Mn}\right)$ called duralumin is light as well as strong. It is used for making aircraft bodies and parts, space satellites and kitchenware.

The properties of an alloy are different from the properties of the constituent metals:

1. Alloys are stronger than the metals from which they are made.
2. Alloys are harder than their constituent metals.
3. Alloys are more resistant to corrosion.
4. Alloys have lower melting points than constituent metals.
5. Alloys have lower electrical conductivity than pure metals.

Explanation of correct option:

• Steel is an alloy of metal iron $\left(\mathrm{Fe}\right)$ and non-metal carbon $\left(\mathrm{C}\right)$.

Explanation of incorrect options:

• Brass is an alloy of two metals, copper $\left(\mathrm{Cu}\right)$ and zinc $\left(\mathrm{Zn}\right)$ .
• Bronze is an alloy of two metals, copper $\left(\mathrm{Cu}\right)$ and tin $\left(\mathrm{Sn}\right)$.
• Amalgam is an alloy of metal mercury $\left(\mathrm{Hg}\right)$ with one or more metals.

Hence, the correct option is (D).