Quantify and quantization youre saying have different root words? their similarity in definition and to the Latin word quantus is just coincidence? (whoops nitpicky ahem ahem)

And of course it was hypothesized but never proven, double slit pushed it towards theory/fact

but also I'm not sure if you know where the line of quantum mechanics to newtonian mechanics are, cause newton definitely didn't theorize too much about the energy of light