Question

Which of the following is not a homogeneous material?
A. Alloys
B. Ceramics
C. Metals
D. None of the above

Answer 1

Materials are made of various particles that are not even visible to our naked eyes, particles such as colloids, true particles etc. Various materials are a mixture of different particles on the basis of which the materials have been classified as homogeneous and heterogeneous particles.

Complete step by step answer:
Let us further know more about homogeneous and heterogeneous materials. So, a material of uniform composition all over the material such that it cannot be physically separated into various constituents or particles whereas heterogeneous materials are those materials that are a combination of different types of materials existing in different phases and can be physically sorted out. Such materials have non uniforms composition throughout. Now, let us analyze the given compounds one by one and classify them.
Alloys is a homogeneous metallic material which contains two or more metals as a solid solution, and if one of the constituents of alloy is mercury, it is called amalgam. Alloys are made by fusing, reducing and compressing various compositions of metals. Therefore it has a uniform composition and cannot be manually separated back into its constituents. Similarly metals are naturally occurring homogeneous materials and therefore are a uniform composition of certain impurities and elements which can only be separated out by the complex process of froth-floatation and furnaces. Ceramics or cement is a homogeneous mixture of clay, porcelain and cement, it is a hard, heat resistive material that can not be separated manually.

Therefore the answer to the question is option D.

Note: Even the purest metals are refined by mechanical complex processes like extraction which are quite costly therefore making these metals more expensive. Metals are present in nature in the form of ores they need to be refined for normal use.