Bonds In Focus

Droplets of water roll off a plant after rain. Each bead is a globular window into the world, reflecting everything around it. Due to the hydrogen bonds that form between water molecules, water has the special properties of adhesion and cohesion. On this leaf alone, both special properties are demonstrated. Adhesion allows water to stick to many other surfaces, which is why these beads of water remain on the leaf despite its slanted orientation. Cohesion allows water to stick to itself, which is why these drops of water have formed into beads; the atoms are drawn towards the center. In the smaller beads of water, the cohesion is stronger, so they are almost spherical and have minimal contact with the leaf; this is due in part to the leaf’s waxy coating that resists adhesion. In the larger bead of water, there is too much contact with the leaf and the mass is too large – cohesion cannot hold the water together; thus, the bead is not as spherical, and instead stretches itself slightly over the surface of the leaf. The unique bonds of water allow it to maintain its beautiful forms.

Socrates Li
Sir John A. Macdonald Secondary School, ON
First Prize ( High School Individual Category )
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