Which of the following statements are correct?

Angle of contact between pure water and silver is 30°

The capillary rise is given by  $\mathrm{h}=\frac{2\mathrm{Tcos\theta }}{\mathrm{\rho gR}}$, where T is surface tension, $\mathrm{\theta }$ is angle of contact and R is radius of meniscus.

The potential energy of molecules in the surface film is greater than that of those molecules which are inside the liquid.
 

A needle can float on clear water but sinks when some detergent is added to it. This is because, the addition of detergent reduces the surface tension of water.