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Why are potassium and caesium, rather li...

Why are potassium and caesium, rather lithium used in photoelectric cells?

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Potassium and cesium have much lower ionization enthalpy than that of lithium. Therefore, these metals on exposure to light, easily emit electrons but lithium does not. Therefore, K and Cs rather than Li are used in photoelectric cells.
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Why are potassium and caesium, rather than lithium used in photoelectric cells ?

Lithium is used photoelectric cells.

Why are potassium and cesium, rather than lithium can be used in photoelectric cells ?

The metal used in photoelectric cell is-

The alkali metal used in photoelectric cell is

Statement-1: Potassium and caesium are used in photo-electric cells. Statement-2: Potassium and caesium emit electrons on exposure to light above certain minimum frequency.

MODERN PUBLICATION-S-BLOCK ELEMENTS ( ALKALI AND ALKALINE EARTH METALS ) -NCERT FILE ( NCERT Textbook Exercises)
  1. In what ways lithium shows similarities to magnesium in its chemical b...

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  2. Explain why can alkali and alkaline earth metals not be obtained by ch...

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  3. Why are potassium and caesium, rather lithium used in photoelectric ce...

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  4. When an alkali metal dissolves in liquid ammonia the solution can acqu...

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  5. Beryllium and magnesium do not give colour to flame whereas other alka...

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  6. Discuss the various reactions that occur in the Solvay process

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  7. Potassium carbonate can be obtained by Solvay's process.

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  8. Why is Li(2)CO(3) decomposed at a lower temperature whereas Na(2)CO(3)...

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  9. Compare the solubility and thermal stability of the following compound...

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  10. Starting from sodium chloride, how will you proceed to prepare (i) sod...

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  11. What happens when (a) magensium in burnt in air, (b) quicklime is heat...

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  12. Describe two important uses of each of the following: (a) casutic so...

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  13. Draw the structure of (i) BeCl2 (vapour) and (ii) BeCl2 (solid).

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  14. The hydroxides and carbonates of sodium and potassium are easily solub...

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  15. Describe the importance of the following: (a) limestone, (b) cement an...

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  16. Why are lithium salts commonly hydrated while those of other alkali me...

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  17. Why it LiF almost insoluble in water while LiCl is soluble not only in...

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  18. Explain the significance of sodium, potassium, magnesium and calcium o...

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  19. What happens when a. Sodium metal is dropped in water? b. Sodium m...

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  20. Comment on each of the following observation: a. The mobilities of t...

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