A laser emitting light with a wavelength of 480 nm is directed toward the surface of rubidium metal. The work function for rubidium metal is 2.16 eV (1 eV = 1.602 x 10-19 J)
No question.
To calculate the energy of the laser light, we can use the equation:
E = hc/λ
Where:
E = energy of the light (in Joules)
h = Planck's constant (6.626 x 10^-34 J·s)
c = speed of light (3.0 x 10^8 m/s)
λ = wavelength of the light (in meters)
Given that the wavelength of the laser light is 480 nm (which is equal to 480 x 10^-9 m), we can substitute those values into the equation to find the energy:
E = (6.626 x 10^-34 J·s) * (3.0 x 10^8 m/s) / (480 x 10^-9 m)
By performing the calculation, we get:
E = 4.14 x 10^-19 J
Next, we need to convert the energy from joules to electron volts (eV). As given, 1 eV is equivalent to 1.602 x 10^-19 J.
So, to convert Joules to eV, we divide the energy value by the conversion factor:
Energy (eV) = (4.14 x 10^-19 J) / (1.602 x 10^-19 J/eV)
By performing the calculation, we find:
Energy (eV) = 2.58 eV
Therefore, the energy of the laser light with a wavelength of 480 nm is approximately 2.58 eV.
Now, let's move on to the work function for rubidium metal. The work function is defined as the minimum energy required to remove an electron from the metal surface.
Given that the work function for rubidium metal is 2.16 eV, we can compare the energy of the laser light (2.58 eV) with the work function.
Since the energy of the laser light (2.58 eV) is greater than the work function (2.16 eV), it means that the laser light has enough energy to overcome the work function and remove electrons from the surface of the rubidium metal.