If an element is radioactive, it refers to the stability of their atomic nucleus. If that atomic nucleus is not stable, it is considered radioactive.
Please specify what you mean by 'i' in an element. If you mean which element has an i in its chemical symbol, some of them are Li, Ni, etc.
a quark or if you mean the smallest element hydrogen
The element was discovered by (insert name of scientist or researcher).
If you mean the most common or 'ubiquitous' element, then it is hydrogen (H).
It is something that is unexpected, as in "There is an element of surprise in this movie."
The element has gained one or more electrons....
Do you mean "What element # is nitrogen?" because the answer to that is 7.
The element has gained one or more electrons....
No it is not an element on the table of elements if that is what you mean.
He refers to Helium element. It is a noble element.
The element has gained one or more electrons....
it is nothing