What gas changes electron beam color as electron speed increases?

[James12345678]

What type of gas would change the colour of an electron beam as the speed of the electrons increases?

 

[davenn]

Hi there James
welcome to PF

an electron beam doesn't have a colour

but exciting a gas with a beam of electrons will cause the gas to glow
this is called fluorescence

have a look at this wiki link
http://en.wikipedia.org/wiki/Cathode_ray

cheers
Dave