Question

Electrons are ejected from a surface with speeds ranging up to 1380 km/s when light with a wavelength of 173 nm is used. What is the work function of this surface? The speed of light is 2.99792 × 108 m/s and Planck’s constant is 6.62607 × 10−34 J · s. Answer in units of eV.

Answer 1

ΔE(work)= 692 Kj/mole e⁻ = 4.32 x 10²⁴ eV/mole e⁻

Step-by-step explanation:

ΔE = hc/λ = (6.63 x 10⁻³⁴j·s)(2.99792 x 10⁸m/s)/(1.73 x 10⁻⁷m) = 1.15 x 10⁻¹⁸j/e⁻ x 6.023 x 10²³ e⁻/mole = 691,999 j/mole e⁻ = 692 Kj/mole e⁻ x 6.24 x 10²¹ eV/KJ = 4.32 x 10²⁴ eV/mole e⁻