Mass, Quantum Numbers and Isotopes
........relative mass.. relative charge
The proton and the neutron don't have [exactly] the same spin. They have nearly the same spin, and because of this, Heisenberg developed isospin theory. Of course, the neutron is neutral whilst the proton has a positive charge. The proton has a mass of 938 MeV whilst the neutron is just slightly higher as 940 MeV. The electron has a negative charge -1, and has a mass of something like 0.510990615 MeV.
The protons and neutrons make up the nucleus of the atom - the heart of all atoms. 99% of the whole mass of the atom is contained within the nucleus. The shell is very lightweight, and is 10,000 times larger than the neutron. The shell itself has no charge. The electron is attracted to the nucleus because they contain a negative charge... Because the charge of the atom and the neutrons are neutral, the electrons are attracted to the positive charge of the proton.
You can work out the numbers of nucleons (that is protons and neutrons).
Number of protons = atomic number of the atom - it is also called the proton number. No of protons + no of neutrons = mass number of the atom.
In this hypothetical atom, let's call it X, what is the atomic number> How many protons and neutrons are there?
To work this out is not difficult. The lowest number at the bottom is 10, which is the proton number - thus, the 19 above calculated the mass number, so 10-19=9 neutrons.
You can also work out the number of electrons inside an atom. The rule to calculate electrons is simple. The number of electrons = the number of protons. This is because the entire charge of the protons must be renormalized by the charge of a negative force (electrons). Electrons are found to orbit the nucleus much like the earth orbits the sun. They are also found to be quite a considerable amount of distance away from the nucleus, in rings called energy levels. Whenever we talk about the electron, we very rarely talk about it as being a particle as such, but rather we speak of its cloud, because that is all the electron was... just a cloud of probability due to the wave function. The most electrons that can be contained on a level is 8. The first level, the inner-most ring will contain 2 electrons. The second and third level contains 8 electrons. After the third level, we move into sublevels... clouds within clouds. The discovery of clouds within clouds is a result of quantizing the atom.
The mass number (more notably the neutron count) can vary within only very small details, and thus can be linked to a process called Isotopes. The most well-known types of isotope are found in carbon elements 12, 13 and 14. Even though they may differ in neutron count, it changes absolutely nothing to the chemical effects of the isotopes.
.........protons neutrons.... mass number
Is the electron a micro black hole?
Brian Greene postulated that the tiny electron could possibly be a micro black hole, but it was briefly hypothesized by Sir Arthur Eddington. If it where a black hole with corresponding values for the mass of the electron and charge, then it would share many intrinsic properties to that of magnetic moments and even Compton wavelength.
In a rotating charged particle, causes a dipole effect, causing the two poles to have magnetic charge, much like the earth has a south magnetic pole and a northern magnetic pole. But the electron must exhibit both spins simultaneously before a strong magnetic field pulls it out of its superpositioning. We use the Schrödinger equation with a 'correction term' which takes into account the interaction of the electron's intrinsic magnetic moment with the magnetic field giving the correct energy. This is what we mean by a magnetic moment. But it is a non-relativistic concept, and accordingly, spin leads the electron into all sorts of disasters... This incongruity is still to be resolved.
When one takes into consideration quantum and relativistic properties, then one can view the Compton wavelength as an expense of knowledge on measuring the position of a particle - this is of course related to the uncertainty principle. We can measure the position of a particle, by hitting light of the particle. However, to measure with accuracy, we need to use a photon with very short wavelength... and here is the interesting part. One may use a photon that exceeds Mc^2 and it may create a new particle when it hits off the object!
Since we have briefly covered magnetic moments and the Compton wavelength, let us continue with the micro black hole hypothesis. Whilst the idea seems very interesting, many problems arise from perceiving the electron as a black hole. First, there is the question to why the electrons do not radiate away energy due to Hawking Radiation... This is a property of all black holes, saying that over time, they will loose mass by radiating it. Electrons don't seem to exhibit this property. However, an answer did come about. It turns out that if the electron is a black hole, it is a very special type that doesn't evaporate.
In spacetime, black holes very close to each other will eventually collide, and when they do, they will shudder space and time, sending out massive gravitational waves... And they will merge into one black hole... So inside an atom, two electrons, assuming they are black holes, would also do the same, but they don't. And even an antiparticle-particle collision would produce a neutral black hole, but they don't, and instead give off two gamma ray energies.
It seems very unlikely that electrons are black holes. Until we can find a more acceptable theory, it will be seen as nothing but a curious hypothesis