Final answer:
Soap negatively affects a paper clip's ability to float by disrupting the surface tension of water, which is initially responsible for allowing the denser steel to remain on the surface.
Step-by-step explanation:
How Soap Affects a Paper Clip's Ability to Float
When a paper clip is carefully placed on the surface of water, it floats due to the surface tension of water. The molecules at the surface of the liquid are pulled downwards into the liquid, creating a tightened surface. This effect allows objects denser than water, like a paper clip, to float when carefully placed on the surface without breaking this tension.
Adding soap to water, however, changes this condition. Soap molecules have two ends: a polar carboxyl salt end that is attracted to water, and a non-polar hydrocarbon tail that is repelled by water. When soap is added to water, these molecules arrange themselves on the surface with the ionic-salt end in water and the hydrocarbon tail sticking out, disrupting the water's tightened surface. This reduction in surface tension means that the ability of the paper clip to float is also diminished or entirely lost, causing it to sink.