Assertion: The crystal structure of calcium fluoride ) is a face-centered cubic lattice.
Reasoning: In each
ion is surrounded by
ions and each
ion is surrounded by
Both assertion and reasoning are true and the reasoning is the correct explanation of the assertion.
Both assertion and reasoning are true, but the reasoning is NOT the correct explanation of the assertion.
Assertion is true, but the reasoning is false.
Assertion is false, but the reasoning is true.
The assertion that the crystal structure of calcium fluoride is a face-centered cubic lattice is true
crystallizes in a cubic crystal structure, known as the fluorite structure. The fluorite structure belongs to the
space group and is characterised by face-centered cubic packing of the anions
with the cations
occupying the tetrahedral interstices. Each
ion is surrounded by
ions and each
ion is surrounded by
ions.
The reasoning provided for the assertion is also true. In the fluorite structure, each ion is coordinated by
ions, which are located at the corners of a cube surrounding the
ion. Each
ion is coordinated by
ions, which are located at the vertices of a tetrahedron surrounding the
ion. This coordination pattern ensures that each ion is in electrostatic equilibrium with its nearest neighbours, and the crystal structure is energetically favourable.
Therefore, option a) "Both assertion and reasoning are true and the reasoning is the correct explanation of the assertion" is the correct answer.