Ch. 1 - Matter I. States of Matter Kinetic Energy States of Matter.
Physical Science 1. Chapter 16 Sec 1 Matter & Temperature KINETIC THEORY OF MATTER- -Matter is made...
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Transcript of Physical Science 1. Chapter 16 Sec 1 Matter & Temperature KINETIC THEORY OF MATTER- -Matter is made...
Physical Science 1
Chapter 16 Sec 1 Matter & Temperature
KINETIC THEORY OF MATTER--Matter is made up of tiny particles in constant motion
* heat them and their speed increases
* tiny particles collide with each other & the walls of their containers
• 4 DIFFERENT STATES OF MATTER
• Solids: definite shape and volume
* arranged in repeating geometric patterns called crystals
* those that aren’t made of crystals are called “amorphous” solids= having no form
* ex. Glass, wax, plastics---some scientists classify them as very thick liquids
States of Matter, cont.
LIQUIDS—definite volume, but takes the shape of container
Particles have enough KE for them to move over and around each other—lets liquids flow
Are NOT compressible– 1 liter cannot be pushed down into smaller container
GASES---no definite shape or volume
Expands or contracts to fill available space
Spreads evenly in all directions Compressible
States of Matter, cont.
PLASMA—most common state of matter in the universe
Gas-like mixture of positively & negatively charged particles
Matter heated to very high temps.---violent collisions
Our sun is plasma, but closer to home what is an example????????
Thermal Expansion-matter expands as it gets hotter & contracts as it cools (except for one very common substance—name it!)
Heat of Fusion- E required to change gas to a liquid
Heat of Vaporization- E required to change liquid to a gas
Water Cycle Earth’s water is 3% fresh,
97% _______ Of the 3% fresh, 2/3 is
locked up in glaciers, deep aquifers & ice (= 2%)
That leaves 1% of Earth’s water for freshwater needs of humans, animals & plants
Human usage: 54% industry, 35% farming, 11% home use
List all the times you have used water today…….
Water cycle, cont. Water molecules stay in the
atmosphere ~ 10 days before condensing & falling as precipitation
Water in lakes remain up to 10 years
In glaciers & deep aquifers, molecules remain for CENTURIES!!!
60-80% of precip that falls returns directly to the atmosphere by evaporation
Evap from plants: transpiration—from holes (stomata) on the underside of leaves
20-40% of precip is run-off or groundwater
Water Cycle Evaporated water (water
vapor) rises, cools & condenses, forming clouds
Vapor condenses around a
condensation nuclei: smoke, pollution, salt
Forms into clouds, 4 types:
CUMULUS—white fluffy clouds that you see on a nice, sunny day
CIRRUS—thin, wispy clouds above 7 km made of ice crystals
NIMBUS—gray clouds that bring rain & snow
STRATUS—thick blanket-like clouds below 2 km
Precipitation
As water vapor droplets collide they become raindrops and when they become heavy enough fall to Earth as:
Rain—liquid droplets
Drizzle—fine liquid mist
Sleet—frozen and liquid drops mixed—freezes on contact
Snow—frozen flakes
Hail—frozen spheres—can get very large
Water Cycle, cont. During recent ice age in
Northern Hemisphere (10,000-15,000yrs ago), water formed into huge glaciers
Very little water returned to atmosphere by sublimation—ice directly to water vapor
Sea level dropped more than 100m (= _______ ft ?)
Precipitation = evaporation; no NEW water is ever introduced into the cycle
SOOOOO, the water you brushed your teeth with this morning could have been used by the dinosaurs
Water Pollution
The addition of foreign materials, compounds, chemicals into our water that reduces its purity
5 types:
Raw sewage: human/animal, depletes oxygen and bacteria cause diseases (typhoid, cholera, hepatitis, E. coli infections, Giardia)
Toxic wastes: manufacturing processes, contaminates groundwater/wells
Fertilizers: algal blooms
Pesticides: stays in fat cells of animals thru-out food chain
Thermal: addition of heated water (power plants)
16-3 Behavior of Gases Pressure: the amount of force
exerted per unit of area
(P= F/ A) Depends on how often the tiny
particles hit container walls
Pascal: the SI unit of pressure (Pa); very small, so most pressures
are stated in KPa (1000 Pa) 1 pascal of pressure = 1 Newton per
sq meter (1Pa = 1 N/ m2) Newton is about the wt of a stick of
butter
At sea level, atmospheric pressure = 101.3 KPa or 101,300 Newtons/sq. meter
Gas Laws Boyle’s Law (Robert 1627-1691, British) if you decrease the volume of a container of gas, the pressure of the gas will increase (provided the temp doesn’t change)
Decrease pressure—volume increases
This is an inverse relationship
Gas laws,cont. Charles’s Law (Jacques
1746-1823, French) volume of gas increases with increasing temp (provided
pressure doesn’t change) Kinetic Theory explains—
heated particles strike walls of container more which increases volume of hot air balloon
This is a direct relationship Empty aerosol cans—put it in
a fire and the remaining particles expand and they can’t increase the volume of the can without the can exploding!!
Absolute Zero Temperature at which all particle motion
would cease Charles found this to be – 2730 C This would be equal to 0 Kelvin In Kelvin there are no negative
numbers---all positive We also do not use a degree symbol with
Kelvin Add 273 to the Celsius reading to get the
Kelvin reading Subtract 273 from the Kelvin reading to get
Celsius
-1050 C = ?K 00 C =?K 700 C = ?K 1000 C =?K 273 K = ?°C 0 K = ?°C 100 K = ?°C 500 K =?°C
Uses of Fluids Archimedes’ Principle- buoyant force on an object in a fluid = weight of the fluid displaced by the object
Buoyant Force- the upward force exerted on an object when it is completely immersed in a fluid; determines whether an object will float or sink in a fluid
Buoyant force < object’s wt =sinks Buoyant force =object’s wt =floats Buoyant force >object’s wt=object
moves upward Floaters/ Sinkers Demo—
decide if the object will float or sink in water
Uses of Fluids, cont. Pascal’s Principle–
pressure applied to a fluid is transmitted unchanged throughout the fluid; hydraulic lifts use this principle
Bernoulli’s Principle— as the velocity of a fluid increases the pressure exerted by the fluid decreases
For example—air speeds over the wing of a plane increase and this decreases the downward air pressure so the higher air pressure under the wing results in a net upward force on the wing, causing lift
Venturi Effect— air flows faster when forced to flow through narrow spaces and as a result the pressure of the fluid drops
This can be a problem in big cities with tall skyscrapers that are close together---the drop in air pressure can cause windows to POP OUT!!
Homework Place a small amount of air
in a re-sealable plastic bag Put bag in the freezer
overnight (describe) Remove bag in the
morning or a few hours later (describe)
Heat the sealed bag with a hairdryer (describe)
What happened? Which law did you just
prove? Attach the bag to your
answers and bag descriptions