Hello there! According to quantum physics, do the electrons have inertial mass? I read somewhere electrons were an amount of energy, with no mass at all. I think I'm confused about the concept of "mass" since I know two, the one they taught me at school, which I'm considering as inertial mass and the one on relativity that is related to energy, right? (Sorry if I'm saying something stupid, I'm sixteen and I actually am new here and the knowledge I have about quantum physics and so on is due to my own research.) Anyway, thanks for the help.