Q.Using the values of work function given in Table 14.1, tell which metal will require the highest frequency of incident radiation to generate photocurrent.

[!TLDR] The threshold frequency $\nu_0=\phi_0/h$ is directly proportional to the work function, so the metal with the HIGHEST work function in Table 14.1 needs the highest frequency to show photoemission -- …

The threshold frequency of a metal is given by $\nu_0=\dfrac{\phi_0}{h}$, which is DIRECTLY proportional to the work function $\phi_0$ (Planck's constant h being the same universal value for every metal). So the metal requiring the HIGHEST frequency of incident radiation to generate any photocurrent at all is simply the metal with the LARGEST work function.\n\nScanning Table 14.1's ten metals -- potassium 2.3 eV, sodium 2.4 eV, calcium 2.9 eV, zinc 3.6 eV, silver 4.3 eV, aluminum 4.3 eV, tungsten 4.5 eV, copper 4.7 eV, nickel 5.0 eV, gold 5.1 eV -- gold has the largest listed work function, 5.1 eV. Its threshold frequency is therefore $\nu_0=\dfrac{5.1\times1.6\times10^{-19}\text{ J}}{6.63\times10^{-34 …

Since $\nu_0=\phi_0/h$ is directly proportional to work function, simply pick the metal with th …

Picking a metal by intuition (e.g. tungsten, associated with high-temperature filaments) rather than actually reading off and co …