Wikibooks: Science: An Elementary Teacher’s Guide/Water, Solutions, and pH

• Format: Book
• Language: English
• Subjects: South Pole; South pole
• Online Access: https://en.wikibooks.org/wiki/Science:_An_Elementary_Teacher%E2%80%99s_Guide/Water,_Solutions,_and_pH

=Unique Properties of Water= Water is the most important liquid in the universe. When NASA looks for life they look for water. Water is a big deal. Water is precious and it has been described by many as coolness in the desert due to its ice cold feeling when entering a heated persons stomach. Humans and most mammals cannot survive more than a few days without water. The ultimate Thirst Quencher. Water is a polar molecule and what makes it polar? Polar like the North and South Pole of the Earth? Yeah similar to those concepts. Polar means to have a double nature nature. And when a molecule is polar it has an uneven distribution of electrons. Some atoms are more greedy or more electronegative meaning they attract and want more electrons than other atoms. An uneven distribution of electrons between bonds means one atom will get more electrons than the other atom and this results in a bond that is more positive on one end and more negative on the other. . . A dipole (2 poles) See on the right how Oxygen pulls the electron density towards itself? Because Oxygen is one of the most electron loving elements on Earth!! A partial positive forms on one end of the molecule (around the Hydrogens) and a partial negative is formed on the other side (around the oxygen). Since every single water molecule has this polarity they are attracted to each other (the positive end of one molecule being attracted to the negative end of another). This creates a stickiness between the molecules and the effect of these small attractions happening millions of times gives water some unique properties. Keep in mind each molecule is jiggling and moving so the bonds between any two molecules may be quickly broken but new bonds form with other molecules. Some of the properties of water that are a product of this weak bonding (which by the way is called hydrogen bonding ) are as follows Water is a liquid at room temperature. Compare water to Carbon dioxide to see why this is unusual CO 2 is a much heavier molecule than H 2 O (an atomic mass of 48 ...