 All processes necessary for life take place in a watery environment.

 Water is a polar molecule.  In water, H’s and O’s do not give up or receive electrons.  Instead they share them between the atoms.  But oxygen ends up being the more negative side of the molecule  The hydrogens end up being the more positive side of the molecule.  It is like a magnet!

 The attraction between the slightly positive hydrogens and the slightly negative oxygen atoms of a different water molecule. Or…  The slightly negative side of different molecules that have oxygen or even nitrogen in them.

1. Cohesion 2. Adhesion 3. Dissolving Ionic Compounds

 The attraction between molecules of the same substance.  So, hydrogen bonding makes water molecules stick to each other.

 Examples:  Water forming beads.  Surface tension: Insects walking on water

 The attraction among molecules of different substances.  Water molecules will stick to other things.

 Examples  Water molecules attracted to the side of a graduated cylinder (meniscus)  Helps plants transport water from their roots to their leaves because water molecules stick to the sides of the vessels in the plant that carry water.

 Water breaks ionic bonds so that compounds dissolve in water:  Ex. NaCl  It also attracts polar molecules. Polar molecules are more attracted to water than to each other.  Sugar in Plant Sap

 Solute  The ionic compound getting dissolved  Ex: NaCl  Na + and Cl -  Solvent  The substance that does the dissolving  Ex: Water, H 2 O  Solution  Solute AND solvent  Ex: Salt water: NaCl dissolved in water (H 2 O)

 Non-polar substances do not dissolve in water. They do not carry a charge so are not attracted to water.  Ex. Water and Oil