The most abundant compound that makes up organisms is water \((\text{H}_2\text{O})\). Water is a polar covalent molecule, which means that its electrons are shared unequally between the hydrogen and oxygen atoms. This polarity gives water its unique properties, such as its high surface tension and its ability to dissolve many substances. Water is also an excellent solvent, which means that it is able to dissolve many different types of substances. This property makes water essential for life, as it allows nutrients and waste products to be transported throughout organisms. Water also provides a stable environment for biochemical reactions to occur, and it helps to regulate the temperature of organisms.