The answer would be Rocks, metals, hydrogen compounds, hydrogen and helium, all in gaseous form.
Answer:

Explanation:
2NO₂ ⇌ N₂O₄
E/mol·L⁻¹: 0.058 0.012
K_{\text{eq}} = \dfrac{\text{[N$_{2}$O$_{4}$]}}{\text{[NO$_{2}$]$^{2}$}} = \dfrac{0.012}{0.058^{2}} = \mathbf{3.6}
\\\\
\text{The $K_{\text{eq}}$ value would be $\boxed{\mathbf{3.6}}$}
#protactinium
- It lies in 7th period having Z=91
The outer electronic configuration is 6d^17s^2
- d-block element(transition)
So it will form polar covalent bond (2)
#Francium
Outer electronic configuration 7s^1
It will form ionic bond (3)