How do intermolecular forces affect surface tension?
Stronger intermolecular forces will produce greater surface tension .
The intermolecular forces present in a sample of water are hydrogen bonds . The high surface tension of water allows a paper clip to "float" on the surface of the water. It's not actually floating, it's resting on top of the hydrogen bonds that exist between the water molecules at the surface. See the video below which shows a paper clip resting on the surface of water in a beaker.
If the hydrogen bonds are removed or disrupted, the surface tension will decrease. Watch what happens to the paper clip in the video when detergent (which will disrupt hydrogen bonds) is added to the beaker.
Here is video showing how a paperclip can "float" on water - it's actually being held up by the hydrogen bonds formed between water molecules which give water its surface tension.
Video from: Noel Pauller
Hope this helps!