Latest Questions UpdateCategory: ChemistryChemistry the solid state NCERT questions
Rajiv Sharma asked 3 months ago
  1. Why are solids rigid? Why do solids have a definite volume?
  2. The following solids in different categories based on the nature of inter molecular forces operating in them:
    • Urea
    • Graphite
    • Rubidium
    • Tin
    • Benzene
    • Ammonia
    • Water
    • Zinc sulphide
    • Argon
    • Silicon carbide
    • Potassium sulphate
  3. Name the parameters that characterise a unit cell.
1 Answers
Education Desk Staff answered 3 months ago
Question : Why are solids rigid?
Answer
The constituent particles in solids have fixed positions and can oscillate about their mean positions. Hence, they are rigid.
The constituent particles of a solid have fixed positions and are not free to move about, i.e., they possess rigidity. That is why they have definite volume.

Question: Name the parameters that characterise a unit cell.
Answer
A unit cell is characterised by following parameters:
The angles between the edges: α (between b and c); β (between a and c) and γ (between a and b)
The dimensions of unit cell along three edges: a, b and c.

Question: The following solids in different categories based on the nature of inter molecular forces operating in them:
Answer
Urea : Molecular (polar)
Graphite : Covalent
Rubidium : Metallic
Tin : Metallic
Benzene : Molecular (non-polar)
Ammonia : Molecular (H-bonded)
Water : Molecular (H-bonded)
Zinc sulphide : Ionic
Argon : Molecular (non-polar)
Silicon carbide : Covalent
Potassium sulphate : Ionic

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