Threshold wavelength for sodium photoelectric effect is 5000 Å. Its work function is approximately:
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Threshold wavelength for sodium photoelectric effect is 5000 Å. Its work function is approximately:

G1 Physics · Accepted Answer

Work function W = hc/λ₀ = (6.626 × 10⁻³⁴)(3 × 10⁸)/(5000 × 10⁻¹⁰) ≈ 3.98 × 10⁻¹⁹ J. Answer: A.