Which of the following elements has the maximum first ionisation potential?

$\int_0^\pi \frac{1}{1+\sin x} \, dx$ is equal to

Which of the following has the maximum boiling point?

Two polaroids are placed in the path of an unpolarized beam of intensity $I_0$ such that no light is emitted from the second polaroid. If a third polaroid,whose polarization axis makes an angle $\theta$ with the polarization axis of the first polaroid,is placed between these polaroids,then the intensity of light emerging from the last polaroid will be

The $P-V$ diagram of a diatomic gas is a straight line passing through the origin. The molar heat capacity of the gas in this process will be:

If $p$ and $q$ are distinct prime numbers and if the equation $x^2 - px + q = 0$ has positive integers as its roots,then the roots of the equation are