a. What is the probability that an electron will tunnel through a 0.50 nm air gap from

Question:

a. What is the probability that an electron will tunnel through a 0.50 nm air gap from a metal to a STM probe if the work function is 4.0 eV?
b. The probe passes over an atom that is 0.050 nm “tall.” By what factor does the tunneling current increase?
c. If a 10% current change is reliably detectable, what is the smallest height change the STM can detect?