Question

J.J. and G.P. Thomson, father and son, both performed experiments with beam of electrons. In 1897, J.J. Thomson deduced electrons are particles with definite value of e/m. In 1927, G.P. Thomson deduced that electrons behave like wave. In J.J. Thomson experiment,electrons with kinetic energy 200 eV passed through a pair of plates of 2cm separation. Explain why J.J. Thomson show no evidence for wave like behavior of electrons.