It's generally okay to ignore relativistic effects when a particle's speed is less than 1.0% of the speed of light.
Find the accelerating potential difference that will bring electrons to that speed, starting from rest.
Find the accelerating potential difference that will bring protons to that speed, starting from rest.
Find the accelerating potential difference that will bring alpha particles (helium nuclei, consisting of two protons and two neutrons) to that speed, starting from rest.