A metal foil has a threshold frequency of 5.45× 1014 Hz. Which of the colors of visible light have enough energy to eject electrons from this metal.
Convert 5.45E14 Hz to wavelength in meters and convert to energy required.
c = freq x wavelength
Then convert the low end and the high end colors (4000 Angstroms low end and 7000 Angstroms high end) to energy and compare.
yellow
green
To determine which colors of visible light have enough energy to eject electrons from a metal foil, we need to consider the concept of the photoelectric effect and the relationship between the energy of a photon and its frequency.
The threshold frequency (f₀) of a metal is the minimum frequency of light required to eject electrons from its surface. In this case, the threshold frequency is given as 5.45 × 10^14 Hz.
According to the photoelectric effect, electrons will be ejected from the metal surface only if the energy of the incident photons is greater than or equal to the energy required to overcome the binding energy of the electrons in the metal. The energy of a photon can be calculated using the equation:
E = h × f
Where E is the energy of the photon, h is Planck's constant (6.63 × 10^-34 J·s), and f is the frequency of the photon.
To determine which colors of visible light have enough energy to eject electrons from this metal, we need to compare the energy of each color of visible light with the threshold energy.
The visible light spectrum ranges from approximately 4.3 × 10^14 Hz (violet) to 7.5 × 10^14 Hz (red). Any color of light with a frequency higher than the threshold frequency (5.45 × 10^14 Hz in this case) will have enough energy to eject electrons from the metal.
Therefore, colors such as violet, indigo, blue, green, and yellow will have enough energy to eject electrons from the metal foil, while colors such as orange and red will not have enough energy.
By comparing the frequency of each color of visible light with the threshold frequency, we can determine which colors have enough energy to eject electrons from the metal foil.