contestada

What is the maximum kinetic energy of ejected electrons when photons of wavelength 300 nm hit a metal that has a work function of 1.13 ev? A. 0.50 ev B. 1.0 ev C. 2.0 ev D. 3.0 eV E. 4.0 ev

Respuesta :

Explanation:

Given that,

Wavelength of the photon, [tex]\lambda=300\ nm=3\times 10^{-7}\ m[/tex]

Work function of the metal, [tex]\phi=1.13\ eV=1.81\times 10^{-19}\ J[/tex]

We need to find the maximum kinetic energy of the ejected electrons. It can be calculated using Einstein's photoelectric equation as :

[tex]hf=E_k+\phi[/tex]

[tex]E_k=hf-\phi[/tex]

[tex]E_k=h\dfrac{c}{\lambda}-\phi[/tex]

[tex]E_k=6.63\times 10^{-34}\times \dfrac{3\times 10^8}{3\times 10^{-7}}-1.81\times 10^{-19}[/tex]

[tex]E_k=4.82\times 10^{-19}\ J[/tex]

[tex]E_k=3.01\ eV[/tex]

or

[tex]E_k=3\ eV[/tex]

So, the maximum kinetic energy of the ejected electrons is 3 ev. Hence, this is the required solution.