13.9k views
5 votes
What is the binding energy in eV of electrons in magnesium, if the longest-wavelength photon that can eject electrons is 337 nm?

a) 3.68 eV
b) 2.71 eV
c) 1.24 eV
d) 5.68 eV

User Stefaan
by
7.8k points

1 Answer

4 votes

Final answer:

The binding energy of electrons in magnesium, given the longest-wavelength photon that can eject electrons is 337 nm, is approximately 3.68 eV.

Step-by-step explanation:

To find the binding energy of electrons in magnesium for a longest-wavelength photon of 337 nm that can eject electrons, we will use the equation for the photoelectric effect, which relates the energy of a photon to its wavelength:

E = hf = \(\frac{hc}{\lambda}\)

Where:

  • E is the energy of the photon,
  • h is Planck's constant (6.626 x 10-34 J·s),
  • c is the speed of light in a vacuum (3.00 x 108 m/s),
  • f is the frequency of the photon,
  • \(\lambda\) is the wavelength of the photon.

Converting the given wavelength from nanometers to meters (1 nm = 10-9 m), we can calculate the energy of the photon in joules and then convert it to electronvolts (eV) using the conversion factor 1 eV = 1.602 x 10-19 J:

E = \(\frac{(6.626 x 10-34 J·s) (3.00 x 108 m/s)}{337 x 10-9 m}\) = 5.89 x 10-19 J

E (in eV) = \(\frac{5.89 x 10-19 J}{1.602 x 10-19 J/eV}\) ≈ 3.68 eV

Therefore, the binding energy of electrons in magnesium is approximately 3.68 eV, which corresponds to option a) 3.68 eV.

User Dawnkeeper
by
8.2k points