Materials:
Aluminium - 6,50 * 10^-19
Zinc - 6,88 *10^-19
Silver - 7,23 *10^-19
7.1 Identify the independent variable in this experiment.
7.2 Identify the dependent variable in this experiment.
7.3 Explain what the differences in the work functions of the listed metals in the table mean.
7.4 Violet light, with a wavelength of 410 nm, is shone onto all three of the metal surfaces. Show with a calculation which these metals will emit electrons.
7.5 Calculate the speed of an electron that is ejected from the aluminium surface when UV light, with a wavelength of 170 nm is shone onto the surface.
7.6 What conclusion can be drawn from the photoelectric effect regarding the nature of light?
7.1 The independent variable in this experiment is the type of metal surface (Aluminium, Zinc, Silver).
7.2 The dependent variable in this experiment is the emission of electrons from the metal surfaces when light is shone on them.
7.3 The differences in the work functions of the listed metals in the table indicate how much energy is required to remove an electron from the surface of each metal. A higher work function means more energy is needed to eject an electron.
7.4 To determine which of the metals will emit electrons when exposed to violet light with a wavelength of 410 nm, we can use the formula:
Energy of photon = Planck's constant * speed of light / wavelength
We can calculate the energy of the photon for violet light with a wavelength of 410 nm, and compare it to the work functions of the metals. The metal with a work function lower than the energy of the photon will emit electrons.
7.5 To calculate the speed of an electron ejected from the aluminium surface when UV light with a wavelength of 170 nm is shone onto the surface, we can use the formula:
Energy of photon = Work function + Kinetic energy of the ejected electron
Energy of photon = Planck's constant * speed of light / wavelength
We can calculate the energy of the photon for UV light with a wavelength of 170 nm, and subtract the work function of aluminium to find the kinetic energy of the ejected electron. Then, we can use the formula for kinetic energy to calculate the speed of the ejected electron.
7.6 The photoelectric effect demonstrates that light can behave as both a wave and a particle. It shows that light consists of individual particles called photons, with each photon carrying a specific amount of energy. The intensity of light determines the number of photons, while the frequency of light affects the energy of each photon.