Respuesta :
The velocity of the sodium electrons is [tex]3.5 \times 10^{5}[/tex] m/s
Given the following data:
- Wavelength of light = 400 nanometer.
- Work function of sodium = [tex]4.4 \times 10^{-19}[/tex] Joules
- Mass of sodium = [tex]9.11 \times 10^{-31}[/tex] kg
To find the velocity of the sodium electrons, we would use the equation of photoelectric effect:
Mathematically, the photoelectric effect is given by the formula:
[tex]K.E = hf - BE_i[/tex]
Where:
- K.E represents the maximum kinetic energy of the ejected electron.
- f is photon frequency.
- h is Planck's constant ([tex]6.626 \times 10^{-34}[/tex] J.s).
- [tex]BE_i[/tex] is the work function of the material.
First of all, we would determine the photon frequency of the light.
[tex]Photon\;frequency = \frac{speed}{wavelength} \\\\Photon\;frequency = \frac{3\times 10^8}{4.0 \times 10^{-7}}[/tex]
Photon frequency = [tex]7.5 \times 10^{14}[/tex] Hertz
Now, we can determine the kinetic energy from eqn 1:
[tex]K.E = 7.5 \times 10^{14}(6.626 \times 10^{-34}) - 4.4 \times 10^{-19}\\\\K.E = 4.97 \times 10^{-19} - 4.4 \times 10^{-19}[/tex]
K.E = [tex]5.70 \times 10^{-20}[/tex] Joules.
Also, the kinetic energy possessed by an electron is given by the formula:
[tex]K.E = \frac{1}{2} MV^2\\\\5.70 \times 10^{-20} = \frac{1}{2} \times 9.11 \times 10^{-31} \times V^2\\\\V = \sqrt{\frac{5.70 \times 10^{-20}}{4.56 \times 10^{-31}} }[/tex]
Velocity = [tex]3.5 \times 10^{5}[/tex] m/s
Read more: https://brainly.com/question/16901506