Quantum physics is the study of subatomic particles and their properties. The electron is represented by a probability cloud surrounding a nucleus, this cloud is said to represent the probability of where an electron might be at any given time. Electrons are said to have a negative charge equal and opposite to a proton though only about 1/1000 the mass of a proton. Electrons participate in electromagnetic conversions where the moving of electrons in a similar direction like in a toroid will produce a magnetic field. They also have a spin value, either up or down but when you have a molecule with the ratio of electrons with the same spin you get strange properties such as ferro-magnetism, atoms that will align their ‘domains’ with each other. This means that the electrons in the atom will spin in a direction influenced by an external magnetic field, this property causes the atom to be attracted to the magnetic field. When iron is a liquid and the molecules are free to align their domains, you can place a magnetic field on the material as it forms a solid and you will have a newly formed magnet, this can also be done at room temperature but requires much more energy to move the atoms in a solid.
Electrons form the majority of the space in any liquid or solid, the nucleus of an atom is generally held as being around 10^-13 times the volume of the atom, though this varies across the periodic table in a relatively orderly fashion. The electrons occupy shells or orbits around the nucleus which are very ordered, and have specific energy levels. an electron with a given kinetic energy will occupy a given level away from the nucleus, they will fill the lowest shells before starting to fill the outer shells. An electron is able to jump to a higher shell when it is excited by a photon. The electron will release a photon with a very specific energy when it drops to a space in a lower shell. Any excess energy from the photon is kept as kinetic energy in the electron making it easier for it to jump to a higher shell again. Though technically through Einstein’s equation e=mc^2 we know that the electron will ‘gain a little weight’ when it is holding excess energy. Electrons are easiest to steal from some atoms because they are the only electron in the outermost shell, and the more electrons in the shells below it the more shielding that outermost electron will have from the nucleus. Plasma’s are where most of the electrons have been stripped off the atoms from tremendous energy being pushed into them.
The electron is used as an energy source when either an electromagnetic generator is mechanically powered or from reducing/oxidization half reactions in chemical equations. Batteries are chemical agents which eject and receive electrons, these free electrons are not exactly free, you get into electric potential differences. Electric potential is best described I feel as compressed air. Say you have a wire for electricity to run down, this is the same as a pipe filled with air, the higher the voltage the higher the pressure and the harder it is to get more in. Eventually with a high enough difference in pressure or ‘potential’ you will get a breakdown in the dielectric between the varying potentials. The wires will short and the pipe will explode. There are resistors and regulators and current sources and voltage sources, diodes, inductors, capacitors, amplifiers, etc.
Electrons also are made of subatomic ‘particles’ but at that point quantum physics tends to leave reality and stays in a purely theoretical and mathematical realm.
