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Chemistry · Structure of atom
हिन्दीWhen electromagnetic radiation of wavelength \( 300\text{ nm} \) falls on the surface of sodium, electrons are emitted with a kinetic energy of \( 1.68 \times 10^5\text{ J mol}^{-1} \). What is the minimum energy needed to remove an electron from sodium?
Correct answer · Option 3
\( 2.31 \times 10^5\text{ J mol}^{-1} \)
Explanation
Total energy of incident photon per mole = \( 3.99 \times 10^5\text{ J mol}^{-1} \). Threshold energy \( W_0 = E - \text{K.E.} = 3.99 \times 10^5 - 1.68 \times 10^5 = 2.31 \times 10^5\text{ J mol}^{-1} \).
