Answer:
λ = 3.1824 10-25 m
Explanation:
To release the electron from the power well the absorbed photon electro must be greater than or equal to the energy of the electron in the power well
The photon energy is E_photon = 0.625 J
The speed of light is
c = λ f
Let's use Planck's equation
E = h f
We substitute
E = h c / λ
λ = h c / E
λ = 6.63 10-34 3 108 / 0.625
λ = 3.1824 10-25 m