RADIO EGENFREQUENCIES

When an atom of matter is excited which in physics means it absorbs energy by its electrons, and its electrons go to higher energy states. The atom is said to be excited. When an atom is excited, it may sponataniously  be deexcited or goes to its relaxed state (as Physists prefer to use the words - terms: relaxed, relaxation state, relaxation time) which means the atom's electrons fall back to their basic deexcited state or relaxed state, by emitting the extra energy which they  had  previously absorbed, in the form of an electromagnetic radiation.

Electromagnetic radiation consists of the known long radio waves, the medium radio waves, the short length radio waves, the microwaves, the infra red heat waves, the infra red light, the visible light, the ultra violette light, the x-rays, the hard x-rays and finally, the  ultra hard x-rays. Which kind of electromagnetic radiation an atom will emmit, it depends on the kind of the atom and the amount of energy the atom was previously excited to. However, as far as the total kind of radiation which an atom may emit, it is called the electromagnetic spectrum of the particular  atom and it is a kind of signature for each atom. For example: the E/M spectrum  of Hydrogen, the E/M spectrum of Oxygen,  the E/M spectrum  of Natrium, the E/M spectrum  of Silicon, etc. By radio eigen-frequencies of an atom, we mean the particular characteristic radio frequencies from itrs spectrum. So, we may refer to the radio eigen-frequencies of Hydrogen or the radio eigen-frequencies of Oxygen or we may refer to the particular radio eigen-frequencies of Silicon, etc. 

Why we refer above to a plasma and what a plasma is? Plasma consists of  super excited atoms by either having received very much energy to lose far away an electron or atoms to have received an extra electron from other super excited atom or just available electrons. In either case, these atoms are said to be ionized atoms positively or negatively. So, we may say that a plasma constitutes of ionized atoms of matter with a special behavior and constitute, as phycists say, the fourth state of matter. This means they are not a gas, they are not a liquid, they are not a solid. They are a state of their own, they constitute the fourth state of matter, as Physists say, different from the first three states we know and we referred to them above, as gas, liquid, and solid, See also PLASMA IN SOLIDS, sellection column in the front home page of our site.