Arizona State University (ASU) BIO201 Human Anatomy And Physiology I Exam 1 Practice

Water is characterized as a polar molecule due to its molecular structure and the distribution of electric charge. In a water molecule, oxygen is more electronegative than hydrogen, causing the shared electrons to spend more time closer to the oxygen atom. This results in a partial negative charge on the oxygen and a partial positive charge on the hydrogen atoms. The bent shape of the water molecule further contributes to its polarity, as the dipoles from the hydrogen atoms do not cancel out due to the molecule's asymmetrical geometry. This polarity is significant because it allows water to form hydrogen bonds with other polar molecules and ions, leading to its unique properties such as high surface tension, the ability to dissolve many substances (making it a universal solvent), and its role in biological systems. The polar nature of water also plays a crucial role in essential processes like hydration and biochemical reactions within living organisms.