Which from following compounds is obtained when carbon dioxide gas bubbled through slaked lime solution?

Calculate the number of atoms present in unit cell of an element having molar mass $$190 \mathrm{~g} \mathrm{~mol}^{-1}$$ and density $$20 \mathrm{~g} \mathrm{~cm}^{-3}$$.

$$\left[\mathrm{a}^3 \cdot \mathrm{N}_{\mathrm{A}}=38 \mathrm{~cm}^3 \mathrm{~mol}^{-1}\right]$$

What is the solubility of a gas in water at $$25^{\circ} \mathrm{C}$$ if partial pressure is $$0.18 \mathrm{~atm}$$ ?

$$\left(\mathrm{K}_{\mathrm{H}}=0.16 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~atm}^{-1}\right)$$

What is the radius of fourth orbit of $$\mathrm{Be}^{+++}$$ ?