CdS has a band gap of 2.4 eV. If large crystals of CdS are illuminated with ultraviolet light, they emit light equal to the band gap energy. (a) What color is the emitted light?

Video transcript

Hello everyone. So as to identify the color that is a minute light. If large crystals of zinc cell and I are eliminated with ultraviolet light. Considering that it has a band gap of 2.58 electron volts. So we need to first calculate the wavelength of light that corresponds to 2.58 electron volts. You know that the wavelength is Planck's constant times the speed of light by the energy And one electron volt is 1.602. I'm sensing meg of 19 jewels. So the wave month is what we're looking for. Thanks, constant is 6.626 Time since the night of 34. Do some seconds Speed of light 3. times 10 to the eight m/s For the energy 2.58 electron volts And in one electron volt of 1.602 am since the night of 19 jewels. So you get 4.133. I'm spending the night of 19 jaws. So now if you plug in the values for the wavelength It's 6.626. I'm sent in 1934. Do some seconds. Times three I'm sent to the eight m/s. five x 4.133 Tom Stanton A of 19 jewels We get 4.81 Um Centenario seven m. And I need to convert this two nm. There are 4.8, 1 sentence, seven m and in one m we have one times 10 to the nine nanometers And we get 481 nanometers. This wavelength corresponds to blue in the visible spectrum. Thanks for watching my video, and I hope it was helpful.