A metal has a work function of 3.0 eV. What is the thresh...
A metal has a work function of 3.0 eV. What is the threshold frequency of the metal when electrons are just liberated from the metal.(1 eV = 1.6 × 10-19J; h = 6.6 × 10-34Js)
4.8 × 10-19Hz
9.3 × 10-7Hz
4.8 × 1014Hz
7.3 × 1014Hz
9.3 × 1014Hz
Correct answer is D
The work function (ϕ) of a metal is defined as:
ϕ=hf0
f0=ϕh
ϕ=3.0eV=3.0×1.6×10−19
= 4.8×10−19J
f0=4.8×10−196.6×1034
= 0.727×1015s−1
= 7.27×1014s−1
≊
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