The Nature of Water C3: Part 1

1. The Nature of WaterC3: Part 1

2. Density- the amount of mass in a unit of volume • Cohesion- the attraction between water molecules • Polar Molecule- one in which one element pulls on the shared electrons more than the other element

3. Adhesion- attraction of water molecules to other polar molecules • Specific Heat- the amount of energy needed to raise the temperature of 1Kg of a substance 1 degree Celsius

4. Forms of Water • Water exists in 3 states on Earth- solid, liquid, & gas • Water molecules include 2 Hydrogen atoms & 1 Oxygen Atom (H2O) • Water molecules in the liquid state are held close together by weak bonds • When water changes to steam, the molecules move farther apart

5. Latent Heat • When ice melts & when liquid water changes to a gas, heat is absorbed • When water freezes & when water vapor condenses to a liquid, heat is given off

6. Polar Molecule • Cohesion is the attraction between water molecules • It’s what allows water to form into drops • Cohesion also helps keep water liquid at room temperature • If not for cohesion, water molecules would quickly evaporate into air

7. Adhesion is the attraction of water molecules to other polar molecules • An example is in capillary action: when a straw is placed into water, the water appears to ‘climb up’ the straw; this is because the water is attracted to the molecules of the straw

8. Water is a polar molecule; the Oxygen atoms have a partial negative charge & the Hydrogen atoms have a partial positive charge • The polarity of water molecules makes water great for dissolving (the universal solvent)

9. Water is also unique because its solid phase floats on its liquid phase (water molecules are farther apart in ice than in liquid water) • Water has a high specific heat; this means that it takes a lot of heat to increase the temperature of water