And what is mass, really?

I admit that I am not an expert, but I find all of this stuff interesting. So, I am just sending this reply all in good fun.

You said
In terms of mass, you can't make it work either
Mass of proton : 1,6726 x 10^(-27) kg
Mass of neutron: 1,6749 x 10^(-27) kg
Mass of electron: 0,00091x10^(-27) kg

We know that mass and energy are really two states of the same thing.
Also, many (if not all) properties that can be observed of "mass" can be seen in terms of changes in velocity (accelerations - which are caused by the addition of energy). That is why gravity can be observed from accelerations as well as from masses, and time slows down near large masses as well as during accelerations.

According to science, first molecules were the smallest indivisible particles, then atoms, then electrons/neutrons/protons, now quarks. So, we obviously didn't know very much about chemistry/physics and so what makes us think we are significantly closer to understanding it now?

Also. we used to think of electrons, protons and neutrons as particles in the classical sense. In the late 90's, it was shown that the model of the atom works better if you treat the nucleus as classical and the electrons as quantum.

How do we know this model is even correct? What really gives protons and neutrons them more mass? You can ask the same question differently - what gives them more energy? They are in the nucleus and so have less room to move about, so they must need to have more energy to be able to change their velocity frequently enough to stay in their place?

When we think if mass, we think of size. So we think that electrons cannot possibly be made of the same stuff as protons and neutrons because the latter are "larger". But I am wondering what "larger" really means, because I don't think our visualization of it is entirely correct?

I don't know if that made any sense.
Just something to ponder over.

And you are correct, I do need to study more physics, among MANY other things.
Tina.