1. Liquids: Chapter 10 Section 2
By: Joey Belsma, Taylor Cocke, Lauren Gordon, Lauren Jackson & Trip Mixon

3. What is a liquid?
[lik-wid] noun: composed of molecules that move freely among themselves but do not tend to separate like those of gases; not gaseous nor solid
Definite volume but not a definite shape.
Takes the shape of its container
The particles in a liquid are constantly in motion and are closer together than gas particles due to a greater attraction between the particles (intermolecular force).

4. Liquids are Fluids
The kinetic-molecular theory of liquids states that the particles within a liquid are not bound together in a fixed position.
Fluid: A substance that can flow and therefore take the shape of its container
Gases and liquids are fluids

5. Properties of Liquids Relatively high density
Relative incompressibility
Ability to diffuse
Surface tension
Evaporation and boiling
Formation of solids

6. High Density
Due to the close arrangement of liquid particles, substances in a liquid state are hundreds of times denser in normal atmospheric pressure than they would be as a gas.
Liquid substances are usually only 10% less dense than in a solid state of matter
Water is an exception
*At the same temperature and pressure, different liquids can differ greatly in density

7. Relative Incompressibility
Liquids are not as compressible as gases because liquid particles are packed closer together.
When liquid H2O is at 20 degrees Celsius and is compressed with 1000 atm, the volume only decreases 4%.
Gas would be 1/1000 of its volume
Pressure from liquids act in all directions

8. Ability to diffuse
The constant motion of liquid particles cause diffusion.
Diffusion is slower in liquids than in gases
Attractive forces between the particles in liquid slow their movement
As temperature increases, diffusion speed increases
Average KE (speed of moving particles) is increased

9. Surface tension
Surface Tension: A force that tends to pull adjacent parts of a liquid’s surface together, thereby decreasing surface area to the smallest possible size.
Result from the attractive forces between liquid particles
Water has the highest surface tension
Capillary Action: the attraction of the surface of a liquid to the surface of a solid
This attraction pulls the liquid molecules upward along the surface against the pull of gravity
Transportation of water from the roots of a plant to its leaves

10. Evaporation and Boiling
Vaporization: the process by which a liquid or solid changes to a gas
Evaporation: the process by which particles escape the surface of a nonboiling liquid and enter the gas state
Evaporation is a form of vaporization
Evaporation occurs because the particles of a liquid have different kinetic energies
Boiling: the change of a liquid to bubbles of vapor that appear throughout the liquid

11. Formation of Solids
Freezing: the physical change of a liquid to a solid by removal of energy as heat
When a liquid is cooled, the average KE decreases therefore the particles slow down making the substance a solid