Question

Calculate the maximum wavelength of light that will cause the photoelectric

effect for potassium. Potassium has work function 2.29 eV = 3.67 x 10-19 J.

Answer 1

Step-by-step explanation:

Work function of potassium = 2.29 eV = 3.67 X 10⁻¹⁹ J

So the minimum energy of photon must be equal to 3.67 X 10⁻¹⁹ J .

energy of photon of wavelength λ = hc / λ

where h = 6.67 x 10⁻³⁴

c = 3 x 10⁸

Putting the values in the equation above

6.67 x 10⁻³⁴ x 3 x 10⁸ / λ = 3.67 X 10⁻¹⁹

λ = 6.67 x 10⁻³⁴ x 3 x 10⁸ / 3.67 X 10⁻¹⁹

= 5.452 x 10⁻⁷

= 5452 x 10⁻¹⁰ m

= 5452 A .