Passage V
Fora photon to free an electron from a metal, the photon's frequency, f, must equal or exceed the threshold frequency, fT, for the metal. If f > fT, the photon has extra energy that is transferred to the electron as kinetic energy, resulting in the ejection of the electron from the metal. Kmax is the highest kinetic energy an ejected electron can have for a given f.
Table 1 displays fT for the metals calcium (Ca), magnesium (Mg), mercury (Hg), and platinum (Pt). Figure 1 is a graph of Kmax versus f for each of the 4 metals. Figure 2 is a graph of a photon's energy versus its f.
26. Based on Table 1 and Figure 2, the threshold energy, ET, for Hg is closest to which of the following?
Your Answer is
Correct Answer is H
Explanation
Looking at table 1, we know that the fT of Hg is 10.9, corresponding to the abscissa in figure 2 being 10.9, the ordinate is about 7.0