The work function of tungsten is4. 50ev.The wavelength of fastest elec...
HF=KE + H•f•
HC/wavelength=5.5ev+4.5ev
6.626×10^-34Js×3×10^8m/s÷wavelength=10ev×1.6×10-19J
wavelength=(19.89÷16)10^-7m
wavelength=124nm=124000pm
The work function of tungsten is4. 50ev.The wavelength of fastest elec...
Given:
- Work function of tungsten (φ) = 4.50 eV
- Photon energy of incident light (E) = 5.50 eV
To find:
- The wavelength (λ) of the fastest electron emitted from the tungsten surface.
Solution:
The energy of a photon is given by the equation:
E = hc/λ
Where:
- E is the energy of the photon
- h is the Planck's constant (6.626 x 10^-34 J.s)
- c is the speed of light (3 x 10^8 m/s)
- λ is the wavelength of the photon
We can rearrange the equation to solve for λ:
λ = hc/E
Step 1: Convert the given photon energy from eV to Joules.
1 eV = 1.6 x 10^-19 J
E = 5.50 eV * (1.6 x 10^-19 J/eV)
E = 8.8 x 10^-19 J
Step 2: Substitute the values of h, c, and E into the equation for λ.
λ = (6.626 x 10^-34 J.s * 3 x 10^8 m/s) / (8.8 x 10^-19 J)
Simplifying the equation gives:
λ = 2.25 x 10^-6 m
Step 3: Convert the wavelength from meters to angstroms.
1 meter = 1 x 10^10 angstroms
λ = 2.25 x 10^-6 m * (1 x 10^10 angstroms/m)
λ = 22,500 angstroms
Therefore, the wavelength of the fastest electron emitted from the tungsten surface is 22,500 angstroms.
Answer:
The correct option is (c) 12.27.