Question

Which of the following metal is not lustrous?
A.) Calcium
B.) Tungsten
C.) Aluminium
D.) Lead

Answer 1

Hint: By non lustrous we mean the absence of a shiny surface. Knowing the properties of the mentioned elements as options, we can categorize them as lustrous and non lustrous.

Step by step answer:
Lustre is a very common metallic property. Lustre is a way light interacts with the surface of a crystal or rock or mineral.
The first option is Calcium. Calcium is a lustrous metal, having a metallic lustre.
The second option is Tungsten. Tungsten is a lustrous metal that tarnishes in air. So this cannot be the answer. The next option is Aluminium. Aluminium is a lustrous metal, and conducts electricity very well.
Lastly, we have Lead as an option. Lead is an example of a metal which is non lustrous. Lead is a very poor conductor of electricity It is very resistant to corrosion but tarnishes upon exposure to air.

Therefore, the answer of the question is Option D.

Additional Information:
There are basically two types of lustre. Metallic and Non- Metallic. Lustre is an example of intensive property. Lustre is basically a classification of optical properties. Lead, is a heavy metal that is denser than most common materials. Lead is soft and malleable and also has a relatively low melting point.

Note: The lustrous property of the metals is because of the free electrons in them. Usually the lustrous metals are a good conductor of electricity. In case of lead, being non lustrous it is also a relatively poor conductor of electricity.