The work function of sodium metal is 4.41 × 10–19 J. If photons of wavelength 300 nm are incident on the metal, the kinetics energy of the ejected electrons will be (h = 6.63 × 10–34Js; c = 3 × 108 m/s) ______× 10–21 J.
Numerical Value Type
If you are commenting for the first time, please read the guidelines.
If you are answering for the first time, please read the guidelines.
Ans. 222
Sol.
Metal (Work function = E0)
E = E0 + (kE)max
${hC\over\lambda}=4.41×10^{–19}+kE$
${6.63×10^{-34}×3×108\over300×10^{-9}}= 4.41×10^{-19}+kE$
So, (kE)max = 6.63 × 10–19 – 4.41 × 10–19
= 2.22 × 10–19
= 222 × 10–21J
1.1k questions
772 answers
366 comments
77 users