Which elements are highly stable?

The atoms of these elements are highly stable:

Which element forms highest stable oxidation state in its compounds?

Which element is chemically most stable?

How heat of atomisation changes in 3d-series elements are stable?

There is an element It is high stable but it does not contain 's' electros . Guess it .

(A) Atoms of each element are stable and emit characteristic spectrum (R): The spectrum provides useful information about the atomic structure.

Which element represents largest stable atoms?

The transition element that has stable configuration in +1 oxidation state is

(A): Oxides of II A group elements are stable (R) : Oxides of IIA group elements have high lattice energy.

Nitrogen molecule is highly stable - Why ?