A solution containing 10g of an electrolyte $\mathrm{AB}_2$ in 100g of water boils at $100.52^{\circ} \mathrm{C}$. The degree of ionization of the electrolyte (α) is ______× $10^{-1}$ . (nearest integer)
[Given: Molar mass of $\mathrm{AB}_2=200 \mathrm{~g} \mathrm{~mol}^{-1} \cdot \mathrm{~K}_{\mathrm{b}}$ (molal boiling point elevation const. of water) $= 0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$, boiling point of water $=100^{\circ} \mathrm{C} ; \mathrm{AB}_2$ ionises as $\left.\mathrm{AB}_2 \rightarrow \mathrm{~A}^{2+}+2 \mathrm{~B}^{-}\right]$