Answer;
- It will sink because soap disrupts the inter-molecular forces of water
Explanation;
-A light twig is barely floating on the surface of water. if a drop of dish washing detergent is added near it then it will sink because soap disrupts the inter- molecular forces of water.
-The twig was initially floating due to the force of surface tension created by the inter-molecular forces between water molecules. When soap is added to the water, the twig will be driven to sink by the disruption of the water's surface tension. This is because soap is a surfacant that is amphipathic and thus disrupts the inter-molecular forces between water molecules that are responsible for surface tension.