Select the corrent statement `(s)`
(a) The `C.N.` of cation occupying a tetrahedral hole is `4`
(b) The `C.N.` of cation occupying an octabedral hole is `6`
(c ) In schottky defects, density of the lattice decreases

In a hypothetical solid C atoms form C C P lattice with A atoms occupying all the Tetrahedral Voids and B atoms occupying all the octahedral voids A and B atoms are of the appropriate size such that there is no distortions in the CCP lattice. Now if a plane is cut ( as shown ) then the section would like

In a hypothetical solid C atoms form C C P lattice with A atoms occupying all the Tetrahedral Voids and B atoms occupying all the octahedral voids A and B atoms are of the appropriate size such that there is no distortions in the CCP lattice. Now if a plane is cut ( as shown ) then the section would like

Assertion: In a crystal, the size of the cation is larger in a tetrahedral hole than in an octahedral hole. Reason: Cations occupy more space than atoms in crystal packing

Defects which do not disturb the stoichiometry are called stochiometric defect. At the time of crystal formation an ion may not occupy its expected position leaving a void or hole at that site. As a metter of fact one positive and one negative ion are missing from their respective positions leaving behind a pair of holes. This vacancy is a Schottky defect. Due to this defect density decreases. Defect arises in which certain atoms or ions have migrated to interstitial position some distance removed from the holes which they vacated. In this case there is no change in the density of the crystal. In the Schottky defect