- Oct 2017
No, it's an upward molecular force, which balances the weight of the pin.Isn't those molecules that are at curved surfaces gonna feel a downward intermolecular force due to molecule below it, and it should cancel the upward attraction caused by the molecule above it.
Maybe this picture will help:
Source: Surface tension - Wikipedia
Notice the directions on the arrows... the van der Waal's forces act to make the water "stickier", not "slippier".