Refractive index of a solid is observed | Class 12 Chemistry Chapter The Solid State, The Solid State NCERT Solutions

Previous / historical NCERT chapter

This chapter belongs to a previous NCERT/CBSE curriculum and is not part of the current 2026-27 chapter list. Removed in 2022-23.

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter The Solid State. This page offers a step-by-step solution to the specific question from Exercise 1, Question 5:

Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?

. With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 5:

Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?

Answer:

The solids are classified into two types:

a) Crystalline /true solids

b) Amorphous solids

To distinguish between crystalline and amorphous solids, isotropy and anisotropy plays a vital role.

Isotropy – The substances which have the same physical properties such as electrical conductivity, thermal conductivity, mechanical strength, refractive index etc. in all the directions in the space are called isotropic substances and this property is called as isotropy.

Anisotropy – The substances which have physical properties such as electrical conductivity, thermal conductivity, mechanical strength, refractive index etc. different in different directions in the space are called anisotropic substances and the property is called as anisotropy.

So a isotropic solid will have same refractive index in all the directions. Hence, amorphous solids are isotropic in nature. The reason for this is that in amorphous solids the arrangement of particles is random and disordered, therefore all directions are equivalent and properties are independent of direction .On the other hand, the particles in a crystalline solids are arranged & well ordered. Thus the arrangement of particles may be different in different directions.

 CLEAVAGE-A crystalline solid when cut with a sharp edged tool such as knife gives a clean cleavage but an amorphous solid undergoes an irregular cleavage i.e. when an amorphous solid is cut with a sharp edged tool, it cuts into two pieces with irregular surfaces.


Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about The Solid State.
  • Review previous year question papers to get an idea of how such questions may be framed in exams.
  • Practice answering questions within the time limit to improve your speed and accuracy.
  • Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 5: Refractive index of a solid is observed to have the same value along all directions. Comment on the ....

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