Suffix
The word element that requires a combining vowel for attachment when it begins with a consonant is known as a combining form. This helps to ease pronunciation and maintain the integrity of the word root.
Atom
A metalloid :)
It wouldn't
Pixel
a sheetlike indirect attachment to a skeletal element
It is possible if the element undergoes nuclear decay. But this is possible only for unstable isotopes.
oxygen h2o
Maybe it can be electrons or mass numbers
That would be either Americum, named after America, or Europium, named after Europe.
The valence value of an element is the number of electrons that an atom can gain, lose, or share in order to achieve a stable electron configuration. It determines the element's ability to form chemical bonds with other elements.
Probably not in English, with its double consonant beginning. But there is an element Niobium, similar in effect to Tantalum.