Ans. Preparing the Chapter 1 solid-state needs a clear understanding of the physical properties. For this, students must need to understand the difference between crystalline and amorphous solids with deep detail about this topic. Students should also get a clear view of the difference between unit cell and crystal lattice, cubic close packing and hexagonal close packing, octahedral and tetrahedral void. The NCERT solutions play a major role as reference material for the class 12 students from the exam perspective. The solutions are in very easy language which helps students to get a grip on the important concepts easily.