Spring 2009

Physical Science

Final Review

v6

Study in Chunks

Take breaks

Make it fun!

Areas of Focus… Astronomy

Plate Tectonics

California Resources

Atmosphere

Rock Cycle

Electricity & Magnetism

Nuclear Chemistry

Chemical Reactions

Make flash cards

Write out your notes

Type your notes

Read your notes out loud

Practice! Practice! Practice!

Have a study snack every hour

~ Plate Tectonics ~Location of Rock Layers (age)

Discrepancy of the age of the Earth

Location of fossils

Superposition: the older the layer the deeper it is as long as it has not been disturbed

Earth is about 4.6 billion years (b.y.) old .

The oldest rocks found are only 4.4 b.y. old because the oldest rocks were recycled.

Seismographs measure earthquake waves.

The primary wave is the fastest moving front-to-back

The secondary wave is next fastest moving side-to-side

The surface wave moves on the surface, is the slowest and does the most damage.

Earthquakes occur at plate boundaries and where there are volcanoes.

~ Plate Tectonics ~

Evidence for plate tectonics

Patterns of plate movement

Earthquakes & Volcanoes

Types, Location on plates, effects on Earth

Fossils are found in Antarctica because Antarctica used to be at the equator.

Ridges, magnetic strips, abyssal plain, hot spots with island arcs and trenches all prove that the ocean plates move.

Folded mountains, form where continental plates converge, (come together). Example: Mt. Everest

Mauna Loa (in Hawaii) is a hot spot Volcano with a shield shape because the lava is basalt and very runny.

Ocean plates converging with continental plates make steep sided subduction zone volcanoes. Examples: Mount St. Helens, Mount Shasta, Mount Fuji

Transform plate motion is where plates grind past each other. Example San Andraes Fault. No volcanoes here.

Lots of earthquakes along transform plate boundaries.

More Plate Tectonics:•Shield volcanoes have continuous outflow of runny lava and are not explosive.

•Explosive volcanoes include the fast rising cinder cones (black Bute) and strato-volcanoes (Mt Shasta and Mt Fuji)

•Earthquakes are measured by seismographs and we use the Richter Scale to measure their magnitude.

•The Richter Scale is a logarithmic scale so that each number is an increase by a factor of 10.

~ Astronomy ~Energy in the sun

The Sun is a medium sized, middle aged star.

Hydrogen fusion powers the stars like the Sun.

H + H He + energy is the fusion of hydrogen equation.

The Sun is half way through its life. It is about 5 b. y. old and it will burn for another 5 b.y..

The stars are much farther away from the Earth than the planets, that’s why the planets look larger in the night sky.

~ California Resources~Geothermal Energy

Earthquakes

Water Resources

Agriculture

Fission of Uranium keeps the magma in the Earth hot.

Geothermal energy comes from magma that is close to the surface of the earth.

When rain water seeps into the Earth and boils from the hot magma, it comes out as steam which can be used to make electricity.

There is geothermal energy in California because we live on a transform fault system

California earthquakes are caused by movement along the faults. The largest fault is the San Andreas along the coastline

The California Aqueduct moves fresh water from the rural Sacramento River/Delta in the north to large cities in the South Example: Los Angeles

California's is the 5th largest economy in the world because of agriculture in the Central Valley.

More Calif. Resources Agriculture is the largest user of fresh water in California

The snow pack in the Sierra Nevada mountains provide us with water runoff all summer.

California has some oil and gas production from our land, but most of the energy for cities comes from out of state.

California is rich in renewable energy resources: wind, rivers, tides, geothermal, and forests.

These are driven by the sun and gravity and are referred to as solar, hydropower, and geothermal energy.

~ Atmosphere~Radiation

Global temperatures

Tilt of the Earth – Sun’s rays

99%of the energy on the surface of the Earth comes from fusion reactions in the sun. Only 1% comes from fission reactions inside the Earth.

Radiant Energy from the sun comes to the Earth as waves, mostly Ultra viloet, visible, and infrared (UV, VIS, and IR)

The equator is the hottest because the sun’s rays are the most vertical and the light is concentrated.

The poles are the coldest because the light is the most spread out.

The seasons are caused by the tilt of the Earth.

More Ocean & Water Cycle

Surface ocean currents are caused by wind and by the Coriolis effect from the spin of the planet.

Deep ocean currents are caused by differences in ocean water density due to temperature and salinity.

There is only one global ocean which we divide into 5 smaller oceans based on location: Pacific, Atlantic, Indian, Arctic, Antarctic. The Pacific is the largest.

The deep currents are driven by the ocean density, which are caused by differences in salinity and temperature.

The main cause of these deep currents is cold water melting from the arctic ocean.

It takes 10 years for water to move around the world in the deep currents, called the conveyor belt.

More on Ocean and Water Cycle

The surface currents are generated from the wind (sun energy) and Coriolis Effect (rotation of the earth).

In the northern hemisphere winds move clockwise and in the southern hemisphere, winds move counter clockwise.

The deep ocean is cold (about 4 C) , dark and very high pressure. It is rich in wildlife forms that have adapted to this harsh environment.

Sulfur based life forms live near deep ocean vents where volcanic out-gassing provides the energy and chemicals, called chemo-synthesis.

Chemo-synthesis provides energy on the dark ocean floor like photosynthesis does on the sunny surface of the Earth.

More Atmosphere About 50% of the sunlight reaches the earth surface to heat it.

About 30 % of the sunlight is reflected back to space by clouds and 20% absorbed by the atmosphere.

White surfaces such as clouds and ice reflect sunlight the most.

Air temperature usually decreases with elevation except in the stratosphere.

About 90% of the incoming UV light is absorbed by the ozone layer in the stratosphere – that is why it is warmer than expected.

The main greenhouse gases are water vapor, carbon dioxide, and methane, but also include nitrous oxides and CFCs

The greenhouse effect gives us a 36 C increase in temperature above the expected, so the average temperature world-wide is about 18 C.

~ Atmosphere~

Weather Patterns

Surfaces of Earth – Sun’s Rays

Early Atmosphere

Photosynthesis

More Atmosphere Weather is what is happening in the atmosphere in 1

day.

Weather occurs in the troposphere because that is where the water is.

Water can be zero to four percent of the atmosphere.

Relative humidity is the amount of water in the atmosphere with a scale of 0 to 100 percent, based on the temperature.

Warmer air can hold more water than cold air.

Climate is the average temperature and precipitation that occurs over a long time.

Large air masses do not mix.

A front develops where 2 air masses bump into each other.

The weather at a front is usually rainy.

The early atmosphere came from volcanic out-gassing. It was rich in carbon dioxide and had no free oxygen.

The free oxygen in today’s atmosphere came from photosynthesis of simple green plants called Cyanobacteria.

Photosynthesis: CO2 + water + sunlight O2 + sugar

~ Atmosphere~

Composition of the Atmosphere

Layers of the Atmosphere

Oxygen

CFCs

Today’s troposphere is made of 78 % N2, 21 % O2 and 1 % other gasses, mostly Argon. There is only .03% CO2.

The atmosphere is divided into layers because the temperature in each layer changes differently as a result of their composition.

Outer space

Exosphere (Magnetic field protects Earth from solar wind)

Thermosphere (Few atoms moving very quickly)

Mesosphere (Coldest layer)

Stratosphere (Contains the ozone layer, protects us from harmful UV light)

Troposphere (Contains most of the air, water and weather)

Earth’s Surface

• People are destroying the ozone layer (O3) by releasing chlorofluorocarbons (CFC’c) from spray cans and air conditioners

More Atmosphere Over 50% of the oxygen in the air we breath comes from

the phytoplankton in the ocean. The other 50% comes from land plants, such as tropical rain forests.

Cold fronts have dramatic storms because warm air masses rise quickly above cold air masses. This produces tornadoes in the Midwest and East coast of the US.

Warm fronts produce lighter storms because warm air masses rise slowly and gradually above cold air masses.

Rain occurs with an air mass rises and cools so that water vapor condenses and precipitates, as solid or liquid.

More on atmosphere The ozone layer protects the Earth from dangerous UV sunlight.

The ozone is destroyed by CFCs, chlorofluorocarbons. These CFCs are human inventions mostly used in refrigeration and air cooling systems.

The ozone “hole” over Antartica, discovered in 1979, has been reversed since CFCs were banned from use in aerosol cans.

Wind blows from high pressure zones to low pressure zones.

Combustion of fossil fuels adds CO2, NOx, and SOx to the atmosphere. These cause global warming, smog, and acid rain.

Biogeochemical Cycles Water, carbon and nitrogen cycle between the Atmosphere,

(gasses) the hydrosphere (oceans) and the lithosphere (rocks) on Earth.

97% of the water is in the ocean (salty).

Most of the fresh water is in the solid phase, ice and snow at the poles and mountain tops. The melting of this solid due to global warming will change the world ecoshperes.

The water cycle: Water evaporates off the ocean, condenses into clouds, precipitates onto the surface. On land it soaks into the ground to become ground water or runs off in rivers back to the ocean.

Salt in the ocean comes from the erosion of land rocks.

Most compounds eroded from the land sink to the ocean floor, stay in the ocean solution, or are taken up by living organisms.

Sodium chloride (NaCl) are the main salts in ocean water.

More Biogeochem. Carbon cycles through the atmosphere as CO2 , through the

biosphere as sugars and carbohydrates, through soils as dead organic matter and rocks (lithosphere) as limestone and fossil fuels.

The fossil fuels are coal, oil, natural gas (methane) which are the solid, liquid and gas forms of carbon trapped underground.

Nitrogen is 78% of the air as an inert gas, N2.

There are 2 ways living organisms (biota) can get inorganic nitrogen from the abiotic (nonliving) environment.

1. Soil microbes “fix” N2 from the atmosphere and move it into the soil.

2. Other soil microbes convert the N2 to nitrate, NO3, which is taken up by plants.

More Biogeochem. Nitrogen is in living organisms in amino acids,

proteins, DNA and RNA.

Carbohydrates, sugars and starch are made of Hydrogen , Carbon and Oxygen (no Nitrogen).

~ Rock Cycle~4 questions…

Classification of Rocks

Pressure and Temperature

Igneous Rocks

Magma

Rocks are named by the process of their formation.

Igneous rocks come from cooling magma.

Intrusive igneous rocks have large crystals. Example: granite.

Extrusive igneous rocks have small crystals. Example basalt.

Sediments are pieces of any rock.

Examples: clay, sand and gravel.

Sedimentary rocks are sediments pressed and cemented together. They contain layers and fossils.

Examples: shale, sandstone, conglomerate and limestone.

Metamorphic rocks are made by heating and squeezing any other rock type.

Examples: schist, slate and marble

~ Electricity & Magnetism~

Schematic Diagrams

Motor

Generator

Series Circuit

Parallel Circuit

Electricity & Magnetism An electric motor converts electrical energy (moving electrons in

a wire) into mechanical energy (rotation).

A generator converts mechanical energy (rotation) into electrical energy (moving electrons in a wire).

A battery provides direct current DC from a chemical reaction inside the battery case.

The 120V outlet in our homes provides alternating current AC.

Our homes use parallel circuits because parallel circuits all have the same voltage.

Parallel circuits have more than one path for current to flow. The current is split up.

In a series circuit, all the parts share the same current because there is only one path for current to flow. If the circuit “opens” or breaks, then no current flows and no work can be done.

In series circuits the voltage is split up.

Opposite charges attract and create static electricity

Power plants put out so much energy, they measure it in megawatts (millions of watts)

Your home use is measure in kilowatt-hours (power) multiplied by amount of time

Uranium decay fuels electrical generation, called nuclear power.

More Electricity Ohms Law V = I X R, R = V/I, I = V/R

V is electrical potential in volts

I is current in amperes

R is resistance in ohms

If you want to run a 10 amp motor with 10 ohms of resistance then you will need a I x R = 100 volt battery.

Electrical drawings have symbols for all parts and connections. The basic ones are wire, switch, battery, and resisting part (such as a light or a motor).

More Electricity - circuits In a simple series circuit there is only one path for electrons.

Adding a light in a simple series circuit will add work to the system so the first light dims or goes out.

Adding a battery in a simple series circuit increases the voltage additively (1.5 V + 1.5 V = 3.0 V), the light shines brighter

Adding a parallel wire to a circuit gives electrons a choice to which path to take and they take the path of least resistance.

Adding a light in parallel will drain the battery faster, (more current flows)

Adding a battery in parallel does not increase voltage, but does make the battery last longer.

Magnetism Opposite magnetic poles attract.

Magnetic create magnetic fields

Passing a wire through a magnetic field makes electrons move in the wire, generating electricity. All electrical generators are based on this principle.

Motors are the opposite of generators. Electricity in wires make a magnet move. If moved in a circle this creates rotating motion. All electrical tools and appliance with moving parts are based on this principle.

~ Chemistry~Nuclear Chemistry and Radioactivity

Solutions

Organic molecules (names)

Chemical Reactions

Nuclear Chemistry Atom composed of electrons (negative charge), protons

(positive charge), and neutrons (neutral charge)

Neutrons can break up into electron + proton + energy

Alpha particles are made of 2 protons and 2 neutrons (similar to a He nucleus)

Beta particles are high energy electrons

Gamma radiation is the strongest. Gamma is high energy waves that destroys DNA.

When a large nucleus is unstable, it falls apart.

This is called radioactive decay or degradation.

More Nuclear Chem. Protons give elements their chemical properties.

The elements are organized in the periodic table is by protons (atomic number).

The elements in the periodic table are in a pattern called the Periodic Law

The half life is a measure of how fast an isotope of a radioactive element decays (falls apart, fission), some decay very fast and some very slow.

Background radiation is everywhere and is in everything

Fusion occurs in stars and has made all the elements up to iron (Fe)

Supernovas fused together atoms making the elements larger than Fe.

U, P, and K fission fuels the magma heat of the Earth’s interior.

More Nuclear Chem. Nuclear power is electricity that comes from heat from the

radioactive decay of Uranium.

Doctors use radioactive tracers, X-rays and radiation therapy to cure patients.

Cobalt 60 is used to radiate food and medical equipment, sterilizing it inside and out.

The food quality is still good and the food is not cooked or radioactive.

U and P fission were used by the US in WWII as atomic bombs against Japan

H fusion bombs are 1000x more powerful than atomic bombs.

More Nuclear Chem. Half life calculations work like this: If you start with

100 grams of material,

after one half life 50 grams remain,

after 2 half lives 25 grams remain,

after 3 half lives 12.5 grams remain.

And so on…

Radioactive elements, and many eco and social systems of decay follow this pattern, called the ½ life curve..

Organic Molecules Organic compounds (sugar) contain carbon.

When organic compounds dissolve, they split into molecules. They are not charged and do not conduct electricity.

Carbon makes 4 bonds and can form carbon chains of great variety and shapes that are flexible.

Carbon can also double and triple bond to another carbon creating stiffness and rigid shapes, including rings.

Single bonded carbon chains have names that end in “ane”

1 C = methane, 2 C = ethane, 3 C = propane, 4 C = butane, 8 C = octane

Solution Chemistry A solution is a solute dissolved in a solvent.

The solvent is the largest part and it is usually water.

The solute is the smallest part, can be solid, liquid or gas.

A saturated solution can dissolve no more solute at that temperature.

When ionic compounds (e.g. NaCl) called “salts” dissolve, they split into ions (Na+ and Cl-) that are charged and mobile

Only solutions containing free ions will conduct electricity.

~ Chemistry~

Exothermic

Law of Conservation of Matter

calorie vs. Calorie

Fuel

Exothermic reactions get hot.

Endothermic reactions get cold.

Law of conservation of matter: In a chemical reaction there is the same number of atoms before and after the reaction.

A calorie (small “c”) is the amount of heat required to raise the temperature of 1 cc of water by 1 degree Celsius.

A Calorie (capital “C”) is used on on food labels.

One kilocalorie = 1000 calories = 1 Calorie

Law of conservation of enerty: the total beginning energy = the total ending energy.

The energy in exothermic reactions comes from chemical bonds

~ Chemistry~

Reactions

Synthesis reactions make something. Smaller things combine to make larger things

H2 + O2 H2O

Decomposition reactions break up something. Large things yield a larger number of small thingss.

NaCl Na+ + Cl-

In a single replacement reaction, an element by itself replaces an element in a compound.

CuCl2 + Al Cu + AlCl3 In a double replacement reaction, elements or polyatomic

units in two compounds replace each other.

NaOH + HCl Na Cl +HOH

Combustion is the rapid combination of a fuel with oxygen.

CH4 + O2 CO2 + H2O Combustion reactions are exothermic. The products are always CO2 and H2O

More Chemistry A chemical equation shows what you started with (reactants) turn into

what you end up with (products).

The arrow ( )indicates the direction of the change, called a “yield” sign.

Evidence of a reaction include a change in temperature, beginning substances change, new products forming, gasses emitted, color changes

The formulas for the reactants and products represent the compounds and elements that have their own properties, don’t change them!

You balance a chemical equation by multiplying the formulas by coefficients so that…

the number of atoms in the reactants = number in products.

You NEVER change the formulas or the subscripts!!!

Lab Concepts The fire triangle is a simple way of remembering the 3

things needed to sustain a combustion reaction: fuel, oxygen, and a source of heat.

We conducted an experiment measuring the chemical energy in food using a calorimeter setup. Fats and oils have higher chemical energy per unit of mass (calories per gram) than carbohydrates (sugar and starch).

We also conducted an experiment to compare solutions for conductivity. Salts are electrolytes in aqueous (water) solutions. Compounds that do not decompose into ions are not ionic and are not electrolytes.

The End