Final answer:
Electrons with energy less than the binding energy exhibit wave-particle duality, as shown by experiments like Davisson-Germer, where electrons displayed an interference pattern indicative of their wavelike properties.
Step-by-step explanation:
When electrons with energy smaller than the binding energy (denoted as v2 in the context of the provided information) are incident on a surface, they do not have sufficient energy to overcome the metal's work function and therefore, cannot eject electrons from the surface. Instead, what we see is a manifestation of the wave-particle duality of electrons as described by quantum mechanics. The concept of wave-particle duality was demonstrated in the Davisson-Germer experiment, which revealed the wavelike properties of electrons through the appearance of an interference pattern, similarly to light waves, when electrons were diffracted through a crystal. This wavelike behavior can be observed even when electrons pass through the crystal one by one, reinforcing the notion that particles like electrons have both particle and wave characteristics depending on the experimental setup.