Which property of the alkaline earth metals increases with their atomic number?

In good conductors of electricity,the type of bonding that exists is

For any $y \in R$,let $\cot ^{-1}(y) \in (0, \pi)$ and $\tan ^{-1}(y) \in \left(-\frac{\pi}{2}, \frac{\pi}{2}\right)$. Then the sum of all the solutions of the equation $\tan ^{-1}\left(\frac{6 y}{9-y^2}\right)+\cot ^{-1}\left(\frac{9-y^2}{6 y}\right)=\frac{2 \pi}{3}$ for $0 < |y| < 3$,is equal to

The work functions for tungsten and sodium are $4.5 \ eV$ and $2.3 \ eV$ respectively. If the threshold wavelength for sodium is $5460 \ \mathring{A}$,then the threshold wavelength for tungsten is .......... $\mathring{A}$.

What is the correct relationship between the $pH$ values of isomolar solutions of sodium oxide $(pH_1)$,sodium sulphide $(pH_2)$,sodium selenide $(pH_3)$,and sodium telluride $(pH_4)$?

Which one of the following is not included under in-situ conservation?