If the solubility product of AB₂ is 3.20 $$ \times $$ 10^–11 M³, then the solubility of AB₂ in pure water is _____ $$ \times $$ 10^–4 mol L^–1.
[Assuming that neither kind of ion reacts with water]

The atomic number of Unnilunium is _______.

The rate of a reaction decreased by 3.555 times when the temperature was changed from 40^oC to 30^oC. The activation energy (in kJ mol^–1) of the reaction is _______.

Take; R = 8.314 J mol^–1 K^–1 ln 3.555 = 1.268

If the normal at an end of a latus rectum of an ellipse passes through an extremity of the minor axis, then the eccentricity e of the ellipse satisfies :