Which one is an example of a solid solution?

What is the significance of Henry's Law constant $K_H$?

Why is a mixture of $He-O_2$ used by deep-sea divers instead of a $N_2-O_2$ mixture?

If $N_2$ gas is bubbled through water at $293 \ K$,how many millimoles of $N_2$ gas would dissolve in $1 \ L$ of water? Assume that $N_2$ exerts a partial pressure of $0.987 \ bar$. The Henry's law constant for $N_2$ at $293 \ K$ is $76.48 \ kbar$.

The Henry's law constant $(K_H)$ values of three gases $(A, B, C)$ in water are $145$,$2 \times 10^{-5}$,and $35$ kbar,respectively. The solubility of these gases in water follow the order:

Give an example of a solid solution in which the solute is a gas.