top of page

Water

Liquid water is necessary for all living things.  Most importantly, it serves as a medium for moving substances around.  More fluid than its solid form (ice) and more controllable than its gas form (water vapor), liquid water allows cells to get molecules in the right place for performing life functions.

Water molecules are polar - they have a positive side and a negative side that interact differently with other molecules.

  • Water is made of 2 Hydrogen atoms and 1 Oxygen atom held together by polar covalent bonds.

  • The oxygen side is relatively negative

  • The hydrogen side is relatively positive

  • The relative charges cause water molecules to form weak Hydrogen Bonds between molecules.

Because water molecules are polar, they cause certain properties that have effects on living things.

  • Cohesion - water sticking to itself

  • Adhesion - water molecules stick to other substances

  • Solubility - water is the universal solvent - many other molecules dissolve in it

  • High Specific Heat - breaking hydrogen bonds absorbs a lot of energy

  • Density - water becomes less dense when it freezes

bottom of page