Question
40 Panjang gelombang maksimum yang dapat membebaskan elektron daripada permukaan natrium ialah 650 nm. Tentukan tenaga kinetik maksimum bagi elektron yang dibebaskan daripada permukaan natrium jika cahaya dengan panjang gelombang 436 nm ditujukan pada permukaannya dalam vakum.
[ Diberi hc = 1.243 \times 10^3 eV nm, 1eV=1.60 \times 10^{-19} J ]The maximum wavelength able to release electron from sodium surface is 650 nm. Determine the maximum kinetic energy of electron ejected from sodium surface if light of wavelength 436 nm is incident on its surface in vacuum.
[ Given hc = 1.243 \times 10^3 eV nm, 1eV=1.60 \times 10^{-19} J ]
Answer
Hi Farhaini,
When electrons receive energy from photons, some of the energy is used up for the electrons to escape from the metal surface, the remaining energy is the kinetic energy of the electron that escaped. For this question, we are using this formula:
Hope this helps! 
Ouhhh Thank you very much 
