The maximum kinetic energy of electrons emitted from rubidium when it is illuminated by ultraviolet radiation with a wavelength of 315 nm is 1.78 eV. Determine the work function of electrons from rubidium.
To find out the work function of electrons emitted from the alkali metal rubidium, we use the formula: h * ν = Aout + Ek, whence we express: Aout = h * ν – Ek = h * C / λuf – Ek.
Const: h – Planck’s constant (h = 6.62607 * 10 ^ -34 J * s); C – the speed of propagation of light (C = 3 * 10 ^ 8 m / s).
Data: λuf – the wavelength of the considered ultraviolet radiation (λuf = 315 nm = 315 * 10 ^ -9 m); Ek – max. kinetic energy of emitted electrons (Ek = 1.78 eV or Ek = 2.848 * 10 ^ -19 J).
Let’s perform the calculation: Aout = h * C / λuf – Ek = 6.62607 * 10 ^ -34 * 3 * 108 / (315 * 10 ^ -9) – 2.848 * 10 ^ -19 ≈ 3.46 * 10 ^ -19 J = 346 sJ.
Answer: The work function of electrons emitted from the alkali metal rubidium is 346 sJ.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.