How does detergent change the physical properties of water?
Detergents will weaken hydrogen bonds that make water molecules stick to each other. This will decrease the surface tension of water.
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
Notice how the paper clip sank after the addition of detergent to the beaker? That happened because the detergent molecule reduces the attraction of water molecules to each other by disrupting their ability to form hydrogen bonds. The addition of detergent reduced the surface tension of the water.
The reduction of surface tension by detergents is what allows water-detergent solutions to form large bubbles.
Hope this helps!