Our second year Scientific High School students have been studying water properties such as cohesion, adhesion, water surface tension, capillary action and water’s ability to act as a universal solvent. We took some class time conduct a simple experiment demonstrating two of these properties, cohesion and adhesion. Using water, a Pasteur pipette (eye dropper) and a coin, our students set out to answer the question of just how many drops of water fit on a coin.
Thanks to cohesion the water molecules stick to themselves and thanks to adhesion these same water molecules stick to the surface of the coin. As the students began adding water droplets they noticed a unique phenomenon, these properties were causing the water to create a dome. Our class record was an astonishing 87 drops!!!