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What makes the alkali metal halides some...

What makes the alkali metal halides sometimes coloured which are otherwise colourless?

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Meral excess defect due to anionic vacancies leads to the formation of F-centres, i.e. unpaired electrons at the anionic sites. These F-centres impart colour to alkali halides.
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ARIHANT PUBLICATION-THE SOLID STATE -PART III (QUESTION FOR PRACTICE) (Very Short Answer Type Questions)
  1. What type of defect will arise when a solid is heated? Which physical ...

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  2. What type of stoichiometric defect is shown by ZnS?

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  3. What type of stoichiometric defect is shown by AgBr?

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  4. What type of stoichiometric defect is shown by ZnS?

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  5. Why does Frenkel defect not change the density of AgCl crystal?

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  6. The density of a crystal ....... due to Schottky defect.

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  7. Why is the Frenkel defect not found in pure alkali metal halides?

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  8. What is the effect of Frenkel defect on electrical conductivity of sol...

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  9. ........ is an example of ionic compound which shows Schottky defect.

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  10. What type of defect is produced when NaCl is doped with SrCl(2)?

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  11. What makes the alkali metal halides sometimes coloured which are other...

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  12. How may the conductivity of an intrinsic semiconductor be increased?

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  13. Which other element may be added to silicon to make electrons availabl...

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  14. Solid solution of group 13 or group 15 impurities with the group 14 el...

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  15. A group 14 element is to be converted into n-type semiconductor by dop...

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  16. Account for the following: Conductivity of silicon increases on dop...

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  17. Assign reasons for the following: Phosphorus doped silicon is a sem...

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  18. What happens when ferrimagnetic Fe(3)O(4) is heated at 850 K and why?

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  19. Write the type of magnetism observed when the magnetic moments are opp...

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