AP BIOLOGY

Detailed explanation-1: -It seems to defy the laws of physics, but a paper clip made of steel can indeed float on the water surface. The high surface tension helps the paper clip-with much higher density-float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.

Detailed explanation-2: -But when you drop the paper clip trickily, on top of the water surface, it floats. Because the water molecules stay tightly together by attracting other water molecules and form a strong surface tension due to cohesive forces. This surface tension keeps the paper clip floating on the water surface.

Detailed explanation-3: -When you initially drop the paper clip into the bowl of water, it sinks, as the paperclip is too dense.

Detailed explanation-4: -Due to the surface tension, small objects will “float” on the surface of a fluid, as long as the object cannot break through and separate the top layer of water molecules. When an object is on the surface of the fluid, the surface under tension will behave like an elastic membrane.

Detailed explanation-5: -GENTLY place a dry paper clip onto the tissue (try not to touch the water of the tissue) 6. Use the eraser end of the pencil to carefully poke the tissue (not the paper clip) until the tissue sinks. With some luck, the tissue will sink and leave the paper clip floating! What did you see?