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.

1. Crystalline – matter is very orderly; iron or diamond

2. Amorphous – not orderly; rubber, wax and glass

Solid – has definite shape and volume

2 Liquid Properties

1. Surface Tension- a force at the surface of liquid that creates spherical drops

2. Viscosity – a liquids resistance to flow; honey vs water (who’s gonna win )

Liquid – takes the shape of container with definite volume

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.

1. Has no definite shape or volume

2. Conduct electricity (like lightning, fire, and stars)

3. Make up 99% of our Universe

and Plasma

Changes of StateParticles 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)

Changes between solid and liquid

Melting• 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)

Freezing• Changing from a

liquid to a solid

• Water’s freezing point = 0˚C

• Particles begin to slow down to fixed positions

Evaporation• Takes place only on

the surface of a liquid (shrinking puddle, etc)

Boiling

Changes between liquid and gasVaporization - liquid particles gain enough energy to form a gas

• 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

Sublimation – when the surfaces particles of a solid gain enough energy to form a gas

Changes between solid and gas

Solid CO2 = -109.3˚F or -78.5˚C

THE BEHAVIOR OF GASESMeasure gases in 3 ways:

1.Volume – amount of space that matter fills

2.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 PressureHigher pressure has higher # of gas particles per unit volume than low pressure

GAS LAWSCharles’s Law• The volume of a gas

increases as temp increases, and vice versa (proportional)

Boyle’s Law• 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.