MEDIUMMCQ SINGLEJEE Mains ChemistryPhysical ChemistryAtomic StructureIntro

The threshold wavelength for the photoelectric effect on sodium is 5000 Å. Its work function is:

0.4 × 10⁻¹⁹ J
1.1 J
2.2 × 10⁻¹⁹ J
3.3 × 10⁻¹⁰ J
Explanation

W = hc/λ₀ = (2 × 10⁻²⁵ J·m) / (5000 × 10⁻¹⁰ m) = 4 × 10⁻¹⁹ J

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