Question

In 1897 JJ Thomson did experiment with kinetic energies of 200 eV which passed through a pair of plates with 2 cm separation. Use a calculations to explain why JJ Thomson saw no evidence for wavelike behaviour of elecrons.

Answer 1

$E=\frac{hc}{\lambda},\implies$

$\lambda=\frac{hc}E,$

$\lambda=\frac{6.63\cdot 10^{-34}\cdot 3\cdot 10^8}{200\cdot 1.6\cdot 10^{-19}}=0.62~\mu m\ll 2~cm.$