The dust of atoms and molecules(matter) is particles. The solar wind. Isolated electrons and isolated protons. Which forms the building blocks of atomic structure. Neutron and dipole building blocks. A neutron is a dampened dipole. Squeezed shut.
The mass of a particle is not the amount of particle substance, it’s the inertia of the particle. We can not measure the amount of substance, we only measure the force that takes to move it.
The reason a particle has a resistance to an external force, is because the particle is already under a constant balanced acceleration. Under a force. This is the property of inertia. Inertia is the self internal acceleration. Self balanced angular momentum rotating that substance.
This self acceleration can be added to, and/or subtracted from. This is why the “mass” gains….. without adding substance. And why emission happens without losing substance.
When inertia is increased, it takes more force to counter it, or move it, and people think it has gained substance, but it only gained inertia, not substance. Energy into inertia, and inertia back into energy.
Mass is the inertial energy of the only quantum substance, e. A single substance.
Hayseed explanation of matter and it’s inertia, “mass”.
I don’t think gravity is related to mass or inertia, I think it’s related to the number/density of atomic dipoles. A dipole property. Not a particle property. Not a fundamental “matter or mass” property. Solar wind has no gravity interaction, galactic dust does. But dust density rarefies the gravity of it. Solar wind moves extremely fast, dust moves much slower.
But that’s just another hayseed supposition.