Transcript Slide 1
Solids, Liquids, and Gases Chapter 16 Section 1: Kinetic Theory Pages 476- 483 States of Matter Kinetic Theory An explanation of how particles in matter behave. Kinetic Theory states that: All matter is composed of small particles (atoms, molecules, and ions) These particles are in constant, random motion These particles are colliding with each other and the walls of their container. Thermal Energy Thermal energy is the total energy of a material’s particles. Includes kinetic energy - vibrations and movement within and between the particles Includes potential energy - forces that act within the particles. Which has Greater Thermal Energy? Temperature and Kinetic Energy In science, temperature refers to the “kinetic energy” of an object, or how fast the particles in an object are moving. Not how hot or cold an object is. Solids The particles of a solid are closely packed together and are constantly vibrating in place. Most solids have a special type of pattern that the molecules arrange in. Solids Continued Fail Liquids Liquids Continued Particles in a liquid move more freely than particles in a solid. Melting point- the temperature at which a solid begins to turn into a liquid. Heat of Fusion- amount of energy required to change a substance from the solid phase to the liquid phase at it’s melting point. Why do liquids “flow?” Particles in liquids flow because they have more kinetic energy than a solid object and the particles can slide past each other. Gases Gas particles have enough kinetic energy to overcome the forces that hold them together in liquids and solids. Gas particles spread out to fill whatever container they occupy. How does a liquid turn into a gas? It needs enough kinetic energy!!! Called “Vaporization” 2 ways to vaporize: 1. evaporation- occurs at the surface of a liquid 2. boiling- occurs throughout the liquid. Diffusion Diffusion is the spreading of particles throughout a given volume until they are uniformly distributed. Heating Curve of a Liquid Plasma Plasma is matter consisting of positively and negatively charged particles. Expansion Joints…..What for???? Thermal Expansion Thermal Expansion- an increase in the size of a substance when the temperature is increased. Can you think of an example when a liquid expands? As the thermometer is heated, the column of liquid in the thermometer expands. As the temperature cools, the liquid in the thermometer contracts. Can you think of an example when a gas expands? Hot air balloons! The air in the balloon is heated…… the particles in the air move more quickly and expand. Are all solids of a given substance more dense than liquids of the same substance? What do you think? Discuss with your lab partner(s) for 2-3 minutes. Amorphous Solids Amorphous means: without shape So… amorphous solids have no definite crystal lattice shape! Examples are glass and plastics. Neither have a crystal shape to the way the particles align. Liquid Crystals Liquid crystals do not lose the ordered arrangement of their particles like most substances do when they transition from a solid to a liquid. Used in Liquid Crystal Displays, or LCD’s Section 2: Properties of Fluids Pages 485-489 Buoyancy Buoyancy- the ability of a fluid- a liquid OR gas, to exert an upward force on an object immersed in it. Buoyancy Density Density- mass per unit volume. Galileo Thermometers Pascal’s Principle Pressure applied to a fluid is transmitted throughout the fluid. Bernoulli’s Principle As the velocity of a fluid increases, the pressure exerted by the fluid decreases. Example: Viscosity The resistance to flow by a fluid. Water has a low viscosity because it flows easily. Syrup had a higher viscosity. Section 3: Behavior of Gases Pages 490-495 Pressure Pressure is the amount of force exerted per unit of area Boyle’s Law Decreasing the volume of a container of gas and holding the temperature constant will cause the pressure of the gas to increase. Charles’ Law The volume of a gas increases with increasing temperature as long as pressure does not change.