Cathode ray
Properties
Properties
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Like a wave, cathode rays travel in straight lines, and produce a shadow when obstructed by objects. [Ernest Rutherford](/wiki/Ernest_Rutherford "Ernest Rutherford") demonstrated that rays could pass through thin metal foils, behavior expected of a particle. These conflicting properties caused disruptions when trying to classify it as a wave or particle. Crookes insisted it was a particle, while Hertz maintained it was a wave. The debate was resolved when an electric field was used to deflect the rays by J. J. Thomson. This was evidence that the beams were composed of particles because scientists knew it was impossible to deflect electromagnetic waves with an electric field. These can also create mechanical effects, fluorescence, etc.

[Louis de Broglie](/wiki/Louis_de_Broglie "Louis de Broglie") later (1924\) suggested in his doctoral dissertation that electrons are like photons and can act as [waves](/wiki/Matter_wave "Matter wave"). The wave\-like behaviour of cathode rays was later directly demonstrated using reflection from a nickel surface by [Davisson and Germer](/wiki/Davisson%E2%80%93Germer_experiment "Davisson–Germer experiment"), and transmission through celluloid thin films and later metal films by [George Paget Thomson](/wiki/George_Paget_Thomson "George Paget Thomson") and Alexander Reid in 1927\. (Alexander Reid, who was Thomson's graduate student, performed the first experiments but he died soon after in a motorcycle accident and is rarely mentioned.)


What behavior was expected of a particle?