Unit 3: Thermal Energy Flashcards
Liquds
Have a definite volume but take the shape of their container. The particles move fast enough to overcome some of the attraction between them. The particles are close together but can slide past each other.
Special properties of liquid
Surface tension: a force that acts on the particles at the surface of a liquid. This causes liquids to form spherical drops.
Gasoline has a pow surface tension and forms flat drops
Viscosity: a liquid’s resistance to flow. Usually the stringer attraction between molecules of a liquid, the re viscous it is. Example: water has a lower viscosity than honey
Gas
No definite shape or volume. Particles of gas move fast enough to overcome almost all of the attraction between them. The particles are far apart and move independently of each other.
Thermal expansion
Thermal expansion is the increase of the size of a substance in response to an increase in the temperature of the substance. As the temperature increases, the particles move faster and spread out.
Evaporation-boiling
Evaporation is when vaporization takes place at the surface of the liquid
Boiling is when vaporization takes place below the surface
Kinetic energy/temperature
More KE= higher temperature
Faster that the particles move=more KE
Sublimation
Solid to gas
Example: dry ice (solid CO2) becomes a gas (co2)
Deposition
Gas to solid
Example: snow forming in clouds
Solid
Solids have a definite shape and volume. Particles of a solid do not move fast enough to overcome the attraction between them. So they remain close together and vibrate in place.
There are two kinds of solids:
Crystalline solids: very orderly three dimensional arrangement of particles. They are in repeating patterns of rows. Examples: iron, diamonds, ice, quartz
Amorphous solids: no special arrangement of particles. Examples: glass, wax
