Lecture: Phases of Matter

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What is “phase” of matter?

What controls phase of matter?

Draw a picture of YOUR favorite phase of matter, and say why it is?

1. Matter is defined as: ?mass and volume

2. Properties of matter: two categories:A. Physical: how an object appears/to change

1. mass: ?2. volume: ?3. density: ?4. color: ?5. shape: ?6. hardness:?7. texture:?8. phase change:?

B. Chemical: how it changes into a new substance: reactivity (w/bonds broken or formed)

3. Characteristic properties: are indicators of substances (not an indicator of an object) like DNA is an indicator of species or organism: A. freezing point (phase change)B. melting point (phase change)C. boiling point (phase change)D. densityE. solubilityF. flammability

4. Phases of matter: same substance w/ different amounts of energy (molecule spacing will change too): 4 phases:

solid, liquid, gas and plasma

A. Solid1. definite shape and definite volume2. very little movement:

Brownian motion(?) only: -due to very little kinetic energy of e-

3. frozen in space: - does this mean cold?- molecules locked in place: frozen -not always cold: your desk, hair?

4. lowest energy state, why?

B. liquid:

1. definite volume

2. shape fits container up to a level

3. molecules flow:

low viscosity

(= resistance to flow:

honey/oil high viscosity)

4. random molecules arrangement

5. medium amount of energy

C. gas:

1. no definite shape or volume

2. occupies full shape of container

3. high energy:

lots of molecular motion

4. gravity keeps atmospheric gases around the Earth

5. gas laws:

a. Boyles’ law:

as pressure on a gas increases, its volume decreases: P: V

(inverse relationship)

-eardrums, submarines, balloon at the bottom of a pool

b. Charles’ law: as temperature on a gas increases,

volume increases: T: V

(direct relationship)

-car tires, balloon in microwave

D. plasma

1. highest state of energy

2. found in stars, lightning, neon lights

3. most common/abundant phase of matter in the universe, why?

4. atoms begin to break down:

e- disassociate from nuclei = ionize

5. Phase change (phase molecular model demo)A. energy in the form of heat (kinetic energy) determines the phase (particle excitement)

-intermolecular forces (the molecule to molecule “glue”: keeps shape of substance)

are broken and the substance begins to form a new phase when heated-the atom-to-atom bonds are NOT broken: ie

H2O?- this is why water is liquid at room

temperature and gold is solid at room temperature: - their intermolecular forces are different, gold’s is much stronger.

- how do the intermolecular forces of mercury compare to water (think mercury thermometer)?

B. phase change is a physical change:still the same “stuff”: ice water steamC. melting point:

- temperature from solid to liquid;- freezing point: temperature from liquid to solid- both of these are the same temperature for the same substance, just…

-opposite energy: going into/out substanceD. usually when a solid melts its volume increases,not so with water or bismuth: this is extremely abnormal;

-this is why ice cubes and icebergs float and lakes do not freeze solid.

E. vaporization: changing from liquid to gasF. evaporation: vaporization at the surface of a liquid: breaks intermolecular bonds, releasing energy: sweating?G. boiling point: temperature of change from liquid to gas: steam. Also depends on the pressure of the air at the surface (bp of water at Boulder (94 C) is less than at sea level (100 C): less atmospheric mass: ie dog pile )H. condensation point: temperature of gas to liquid: drips on outside of soda cansI. sublimation: change from a solid to a gas w/o liquid phase: dry ice, iodine, ice cube loss in freezerJ. absolute zero: when all molecular motion stops, even electrons! Thus no Brownian motion.

- Bose-Einstein condensate- 0 degrees Kelvin (-273 C)

Heating/cooling curve:

note when 2 phases are present: temp does not change w/ more energy: it’s a horizontal line:

Fz/mlt pt

Bpt/cond pt

Draw a CO2 sublimation curve (label axis too):

Sublimation curve (dry ice):

solid

gas

Solid and gas

Note: when two phases are present at the same time, the line looks like what?

K. atoms have kinetic energy ?:

Brownian/molecule motion

L. temperature is a measure of:

kinetic energy

- what is your temperature in Celsius? And

what is it actually measuring?

M. phase change maintains the chemical make-up of a substance while

altering the physical arrangement due to

an energy change:

it’s still the same stuff but it looks different