ABSTRACT
Water is the most popular and most important chemical compound on our planet. It is a major chemical constituent of Earth’s surface, and it is the only substance that is abundant in solid, liquid, and gaseous form. Because it is ubiquitous, it seems to be a mild and inert substance. In fact, it is a very reactive compound characterized by unique physical and chemical properties that make it very different from other popular liquids. The peculiar water properties determine the nature of the physical and biological world.
