The threshold frequency of silver is 9.71×1015 Hz. What is the work function of silver?

Question

Planck’s constant is 6.63 × 10−34 J · s. Answer in units of eV.

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Answer 1 · 2018-05-16T22:55:54

#W = 40.2# #"eV"#

Threshold frequency is related to the work function by the following equation:

#f_(0) = frac(W)(h)#; where #f_(0)# is the threshold frequency, #W# is the work function, and #h# is the Planck constant.

We can rearrange this equation to solve for #W#:

#Rightarrow W = f_(0) h#

Let's plug in the given values:

#Rightarrow W = (9.71 times 10^(15) times 6.63 times 10^(- 34))# #"J"#

#Rightarrow W = 6.43773 times 10^(- 18)# #"J"#

However, we need to answer in units of #"eV"#:

#Rightarrow W = (frac(6.43773 times 10^(- 18))(1.6 times 10^(- 19)))# #"eV"#

#therefore W approx 40.2# #"eV"#