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Grade 12Physical Chemistry

Why alkali metals used in photoelectric cells?

Profile image of Raghav
12 Years agoGrade 12
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1 Answer

Profile image of Anjali Ahuja
11 Years ago
Since alkali metals emit electrons when radiation strikes on their surfaces. This phenomenon of emission of electrons when electromagnetic radiation strikes against them is called photoelectric effect. Therefore, alkali metals exhibit photoelectric effect.
One more thing--> Alkali metals used to have low ionisation enthalpies and therefore, the electrons are easily ejected when exposed to light. Among alkali metals, cesium has lowest ionisation enthalpy and hence it can show photoelectric effect to the maximum extent and therefore preffered in photoelectric cell.