[Amps] why a tube fails ?

[Al Kozakiewicz]

>Those extra electrons must be ions (electrons not attached to any nucleus), yes or no?  If they are not all ions, then if electrons are actually added to an atom, then does that change the chemical composition of the metal (a change of its characteristics as given by the Periodic Table of Elements)?  That is, with the addition of electrons, does that make the matter a different element?
 
Ions are atoms where the number of electrons do not equal the number of protons.

Chemically, all elements are determined by the number of protons in the atom. Nothing more.  Ions are created by adding or subtracting electrons.  Isotopes are created by adding or subtracting neutrons.

Adding a proton to iron makes it cobalt.  Subtracting a proton makes it manganese.

Decomposing an atomic nucleus takes very high velocity neutrons,  considerable luck and science and releases large amounts of energy (fission).  Alternatively, you can add very large amounts of energy (temperature and pressure) to combine nuclei and you still release more energy than you add (fusion).  

Al
AB2ZY