Why/how is a paperclip able to float on water?

Water surface tension

Explanation:

The water around the paperclip forms a kind of elastic surface, deforming, in which the clip can stay afloat.

This is because the molecules that are on the surface of the water, already in contact with the air, try to cling to those that are next to them and those that are immediately below.

If we added even if it were just a drop of soap in the water, the clip would go to the bottom, because the soap has the ability to decrease the surface tension of the water.