What is $Endosulfan$?

Which set of elements forms stable,covalently bonded hydrogen-bonded hydrides?

The perimeter of a sector is a constant. If its area is to be maximum,the sectorial angle is:

The formula of azurite is

$A$ photon of energy $8\,eV$ is incident on a metal surface of threshold frequency $1.6 \times 10^{15}\,Hz$. The maximum kinetic energy of the emitted photoelectrons is ...............$eV$ $(h = 6.6 \times 10^{-34}\,Js)$.

Find the value of $-197^{\circ} C$ temperature in Kelvin. (in $~K$)