Which of the following species is not electrophilic in nature?

Which of the following statements are correct for alkali metal compounds?
$(i)$ Superoxides are paramagnetic in nature.
$(ii)$ The basic strengths of hydroxides increase down the group.
$(iii)$ The conductivity of chlorides in their aqueous solutions decreases down the group.
$(iv)$ The basic nature of carbonates in aqueous solutions is due to cationic hydrolysis.

If $f(x) = \frac{1}{1+\frac{1}{x}}$ and $g(x) = \frac{1}{1+\frac{1}{f(x)}}$,then $g^{\prime}(2)$ is equal to

What is Thuringioside?

What is Guayule?

Assume that a drop of liquid evaporates by decrease in its surface energy,so that its temperature remains unchanged. What should be the minimum radius of the drop for this to be possible? The surface tension is $T$,density of liquid is $\rho$ and $L$ is its latent heat of vaporization.