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प्रश्न
Schottky defect is observed in crystals when ______.
पर्याय
some cations move from their lattice site to interstitial sites.
equal number of cations and anions are missing from the lattice.
some lattice sites are occupied by electrons.
some impurity is present in the lattice.
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उत्तर
Schottky defect is observed in crystals when equal number of cations and anions are missing from the lattice.
Explanation:
| Defect | Definition | Type of solid |
Effect of defect on density of substance |
Structure of crystal (with defect) |
| Schottky defect |
A crystal is said to have Schottky defect if equal number of cations and anions are missing from their normal lattice site there by creating vacancies or holes. |
Ionic solid |
Decreases |  Schottky defect in a crystal |
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संबंधित प्रश्न
Out of NaCl and AgCl, which one shows Frenkel defect and why?
Frenkel defects are not found in alkali metal halides because ____________.
The radius of Cs+ is 169 pm and Cl− is 181 pm. The radius ratio is ____________.
Type of stoichiometric defect shown by AgBr is ____________.
Which is not correct about the Schottky defects?
Assertion: No compound has both Schottky and Frenkel defects.
Reason: Both defects change the density of the solid.
Assertion: Due to Frenkel defect, there is no effect on the density of the crystalline solid.
Reason: In Frenkel defect, no cation or anion leaves the crystal.
Which of the following crystals does not exhibit Frenkel defect?
Silver halides generally show:
What is the effect of Frenkel defect on the density of ionic solids?
In a Schottky defect ____________.
Frenkel defect is also known as:
(i) stoichiometric defect
(ii) dislocation defect
(iii) impurity defect
(iv) non-stoichiometric defect
Match the defects given in Column I with the statements in given Column II.
| Column I | Column II |
| (i) Simple vacancy defect | (a) shown by non-ionic solids and increases density of the solid. |
| (ii) Simple interstitial defect | (b) shown by ionic solids and decreases density of the solid. |
| (iii) Frenkel defect | (c) shown by non ionic solids and density of the solid decreases. |
| (iv) Schottky defect | (d) shown by ionic solids and density of the solid remains the same. |
Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion: In any ionic solid (MX) with Schottky defects, the number of positive and negative ions are same.
Reason: Equal number of cation and anion vacancies are present.
Schottky defect is noticed in ______
Given below are two statements:
Statements I: Frenkel defects are vacancy as well as interstitial defects.
Statements II: Frenkel defect leads of colour in ionic solids due to the presence of F-centers.
Choose the most appropriate answer for the statements from the options given below:
The incorrect statement about the imperfections in solids is ______.
Which type of ‘defect’ has the presence of cations in the interstitial sites?
