Final answer:
The photon energy of ultraviolet light is approximately 2.48 eV. These photons will eject electrons from platinum because their energy exceeds the work function of platinum. The maximum kinetic energy of the ejected photoelectrons is approximately 3.87 eV, and the stopping voltage required to arrest their current is around 2.42 × 10^19 V.
Step-by-step explanation:
(a) To find the photon energy of ultraviolet light, we can use the equation:
photon energy = (Planck's constant) * (speed of light / wavelength)
First, let's convert the given wavelength from nm to meters:
wavelength = 150 nm = 150 * 10^-9 m
Now, we can substitute the values into the equation:
photon energy = (6.626 × 10^-34 J s) * (3.0 × 10^8 m/s / (150 * 10^-9 m))
photon energy ≈ 2.48 eV
(b) These photons will eject electrons from platinum because the photon energy (2.48 eV) is greater than the work function of platinum (6.35 eV). According to the photoelectric effect, electrons can be ejected from a metal surface when they absorb photons with energy greater than the work function.
(c) The maximum kinetic energy of the ejected photoelectrons can be calculated using the equation:
maximum kinetic energy = photon energy - work function
Substituting the values:
maximum kinetic energy = 2.48 eV - 6.35 eV ≈ -3.87 eV
However, kinetic energy cannot be negative, so the absolute value should be taken:
maximum kinetic energy ≈ 3.87 eV
(d) The stopping voltage required to arrest the current of photoelectrons can be calculated using the equation:
stopping voltage = maximum kinetic energy/electron charge
Substituting the values:
stopping voltage ≈ 3.87 eV / 1.6 × 10^-19 C
stopping voltage ≈ 2.42 × 10^19 V