Solids, Liquids, and Gases (and Plasmas) Chapter 3 Standard 8.3d – Students will know the states of matter (solid, liquid, and gas) depend on molecular motion.

Solid – has definite shape and volume Crystalline – matter is very orderly; iron or diamond Amorphous – not orderly; rubber, wax and glass

Liquid – takes the shape of container with definite volume 2 Liquid Properties Surface Tension- a force at the surface of liquid that creates spherical drops Viscosity – a liquids resistance to flow; honey vs water (who’s gonna win )

Gases- changes in both shape and volume In a gas, the atoms and molecules are free to move independently, colliding frequently. The particles in a gas are much further apart than between a solid or a liquid.

and Plasma Has no definite shape or volume Conduct electricity (like lightning, fire, and stars) Make up 99% of our Universe

Changes of State Particles at a warmer temp have more thermal energy than particles at a cooler temp Remember: Thermal energy flows as heat from a warmer substance to a cooler substance (ice cream cone melts when outside)

Melting Freezing Changes between solid and liquid Changing from a solid to a liquid Melting occurs at the melting point (water’s melting point = 0˚C and table salt is 800.7˚C) Particles begin to speed up (vibrate quicker) Changing from a liquid to a solid Water’s freezing point = 0˚C Particles begin to slow down to fixed positions

Changes between liquid and gas Vaporization - liquid particles gain enough energy to form a gas Evaporation Boiling Takes place only on the surface of a liquid (shrinking puddle, etc) Takes place when a liquid changes to gas below surface as well as at the surface

Condensation – change in state from a gas to a liquid Gas particles lose thermal energy to form a liquid Cloud formation, fogged up mirrors, water droplets on pop can

Changes between solid and gas Sublimation – when the surfaces particles of a solid gain enough energy to form a gas Solid CO2 = -109.3˚F or -78.5˚C

The Behavior of Gases Measure gases in 3 ways: Volume – amount of space that matter fills Temperature – measure of the average energy of motion of the particles of matter (faster the particles are moving, the greater the energy, thus a higher temp results)

3. Pressure – the force exerted on a surface divided by the total area over which the force is exerted Pressure is measured in units called Pascal's (Pa) High vs Low Pressure Higher pressure has higher # of gas particles per unit volume than low pressure

Gas Laws Charles’s Law Boyle’s Law The volume of a gas increases as temp increases, and vice versa (proportional) As the pressure of a gas increases, the volume of that gas will decrease, and vice versa (inversely proportional) Charles’s Law

Pressure and temperature Recall: The higher the temperature, the faster the molecules are moving When the temp of a gas is increased, the pressure also increases, and vice versa.