So if we examine inside that water droplet, if we get down to the microscopic level, we'll see that the individual water molecules are actually forming relatively strong intermolecular bonds known as hydrogen bonds. So water can form many hydrogen bonds with adjacent water molecules. Now, because hydrogen bonding is stabilizing, that means the water will tend to create a shape that will maximize the number of hydrogen bonds. And it turns out that this spherical shape has the highest volume to surface area ratio and it creates an optimal arrangement of molecules that creates a maximum amount of hydrogen bonds. And that's exactly why the water forms that spherical shape in the first place. So pure water has a high surface tension.