The hydrogen bonds pull the atoms close together in the water to create the water tension on top. That’s why the paperclip can lap on top of the waters “skin”. I would call it a skin because of the way the molecules are gathered tightly together there almost inseparable. But separating them isn’t impossible. Put the paperclip in the water horizontally and it will puncture the “skin” of the water, separate the molecules temporarily and sink to the bottom. But if you just carefully lay the paper clip onto the water vertically, it should