Which of the following is incorrect about Nitrogen?

Question

(1) Nitrogen is a diatomic gas

(2) All halides of Nitrogen are stable

(3) Nitrogen forms 5 oxides

(4) Forms a stable Hydride ($\text{NH}_3$) which is basic

(5) Does not show alltropy

$\begin{array}{1 1} (2)\;and\;(4) \\ Only (2) \\ (1),(3)\;and \;(4) \\ (3) \;and\;(5) \end{array}$