The most common term for atoms of the same atomic number is “electron” or “uncharged particle”. Some common terms include “atomic number”, “atomic mass”, “mass number”, and “mass”.
Atomic number is the number that makes up an atom. The atomic mass is the mass of a single atom. The mass number is the mass of multiple atoms. That means a light atom has the same mass as a heavy atom, but a heavy atom has a much higher mass than a light atom.
The mass number is important because it is a factor in how the atoms interact with one another. The same atom can have different masses depending on how many other atoms it contains, and also depending on how fast it moves through the space between the atoms. A heavier atom can, in theory, be held at a distance that is not too far from the center of the earth, but not too far from the center of the galaxy.
It seems to be a standard argument in physics that when we talk about “atoms” we’re talking about the same thing. There is nothing wrong with that, but it is not a completely accurate way of thinking about atoms. For one thing, atoms are really, really small. They are actually incredibly tiny, and very fragile.
The atomic mass is really, really short. It is not that atoms have different masses, it is that they are different. It can be argued that the mass is a property of the nucleus and the nucleus is a property of the electrons, or something in between. The difference between the atoms in an atom is a property of both the nucleus and the electron(s).
The mass of the nucleus, as well as its electrical charge, is what determines what an atom is made of. If an atom is made of one kind of element, and then is heated to an extremely high temperature, the nucleus will melt, fragment, and turn into another kind of element. The heavier the element, the higher the temperature must be.
The word “atom,” while generally used to refer to the nucleus, is also used to refer to the electrons. The electrons are the little black dudes that are responsible for keeping an atom spinning and moving. A charged particle, called the electron, can’t move unless there is a positively charged nucleus.
Well, yes, the electron is charged. And it’s also the point of charge, the point that makes the nucleus, or the point that makes the atomic mass, or the atomic number. We are talking about the same element, but in two different forms. The electron in the atom and the nucleus in the atom.
This is all good information.
Okay, so we know that the electron and the nucleus are the same thing, but does it explain what’s really going on here? The electron’s motion is like a particle of matter, with its atomic number being one (or the same), but its atomic mass being two (or the same) and its atomic radius being three (or the same).