Science 6

Light causes the excitation of electrons in various molecules, which leads the molecules to eject an electron. The energy of the ejected electron, in joules (J), depends on the type of molecule and the frequency of the light. Figure 1 shows how electron energy varies with light frequency for several different molecules. Figure 2 shows how the number of ejected electrons varies with light intensity, and Figure 3 shows the maximum energy of an ejected electron at a given light intensity for a given molecule.