reactions that an organic compound undergoes in order
to learn about its structure.
Earth Science Reviewer:
What is Science?
(Latin: “Scientia – Which is to know”)
An organized body of knowledge about the natural
universe and the processes by which that
knowledge is acquired and tested
The Scientific method is a method of testing and
evaluation by which hypotheses becomes Theory, and
then Scientific Law.
Observations and Measurements (Qualitative data)
The knowledge that is built by science is always open to
question and revision. No scientific idea is ever onceand-for-all “proved”. Why not? Well, science is
constantly seeking new evidence, which could reveal
problems with our current understandings
Ideas that we fully accept today may be rejected or
modified in light of new evidence discovered tomorrow.
Despite the fact that they are subject to change,
scientific ideas are reliable. The ideas that have gained
scientific acceptance have done so because they are
supported by many lines of evidence.
Hypothesis (a possible explanation)
Experiments (Testing a hypothesis)
Theory (a well-tested explanation)
Law (describes a fundamental relationship of nature)
Hypothesis – And Educated guess
Theory – A Hypothesis that has withstood initial testing
and evaluation. It is intended to be further investigated
by experiment. If the theory does not withstand further
experimentation, it must be modified, replaced, or
rejected Scientists use models as tools to advance their
theories.
Model – It is a miniature representation of a real thing.
Branches of Science
Biological Sciences
Physical Sciences
(Observational
Sciences)
(Measuremental
Sciences)
Biology
Chemistry
Zoology
Physics
Microbology
and etc...
Astronomy
These scientific explanations continually generate
expectations that hold true, allowing us to figure out
how entities in the natural world are likely to behave
(e.g. how likely it is that a child will inhrit a particular
genetic disease) and how we can harness that
understandin to solve problems (e.g. how electricity,
wire, glass, and various compounds can be foashined
into a working light bulb).
References:
1. Shipmen, James T. et. al. “An Introduction to Physical
Science”
2. Glencoc Science: National Geographic. “An
Introduction to Physical Science”
3. Young and Freedman “ University Physics with
Modern Physics”
4. Brown et. al. “Chemistry: The Central Science”
5. Silverio, Angelina, Exploring Life through Science;
Physics: Phoenix Publishing
6. Hewitt, Paul G. Conceptual Physics, 11th Edition, San
Francisco: Pearson, 2010.
Lesson 1: IN THE BEGINNING (Big Bang Theory)
Cosmology –this is a branch of astronomy that involves
the origin and evolution of the universe, from the Big
Bang to today and on into the future.
Meteorology
Geology
Aims and nature of Science:
Science aims to explain and understand
Science, as a collective institution, aims to produce
more and more accurate natural explanations of how
the natural world, what its components are, and how
the world got to be the way is is now.
3 Cosmic Stages
(through which specific groups of elements were
formed)
1.
•Formed the light elements (H,, He, and Li)
2.
Stellar formation and evolution
•formed the elements heavier the Be to Fe
3.
Classically, science’s main goal has been building
knowledge and understanding, regardless of its
potential applications – e.g. investigating the chemical
Big Bang Nucleosynthesis
Stellar Explosion, or supernova
•elements heavier than Fe
Big Bang Theory – This explains how the elements were
initially formed the formation of different elements
involved many nuclear reactions, including fusion,
fission, and radioactive decay.
Nucleosynthesis – this is the process that created new
atomic nuclei from pre-existing nucleons, primarily
protons and neutrons.
Part of its proof is the amount of Hydrogen and Helium
we have in the universe today.
- As the Universe coold, protons and neutrons can fuse
to form heavier atomic nuclei. E.g., Picture 1.6
History of the Universe
Stages of the Big Bang Theory:
Singularity – This is a point in space and/or a moment in
time where they universe was infinitely hot and dense.
Chief nuclear
reactions responsible
for the relative
abundances of light atomic nuclei observed throughtout
the universe.
Recombination – This refers to the epoch at which
charged electrons and protons first became bound to
form electrically neutral hydrogen atoms.
Annihilation – In physics, reaction in which a particle
and its antiparticle collides and disappear, releasing
energy.
Inflation – this is a theory of exponential expansion of
space in the early universe. The inflationary epoch
lasted from 10-36 seconds.
Redshift – This is the displacement of spectral lines
toward longer
wavelengths (the
red end of the
spectrum) in
radiation from distant galaxies and celestial objects.
*If the starlight is blue, the star does not move.
*If the Starlight is red, then the star moves away from
us.
Cosmic Microwave Background (CMB)
- is electromagnetic radiation left over from an early
stage of the universe from the big bang cosmology.
Picture of protostar
The Sun
After sufficient mass and density was achieved in the
Sun, the temperature rose to one million °C, resulting in
thermonuclear fusion. H atom + H atom = He atom +
energy
Protoplanets
Gravitational forces allow the inner planets to accrue
and compact solid matter (including light and heavy
atoms) Solar radiation blew gases (primarily hydrogen,
helium) away from inner planets These gases were
collected and condensed into the gas giants (Jupiter,
Saturn, Uranus, Neptune) Beyond Neptune, ice and
frozen gases form Pluto, Sedna and the Kuiper Belt
Objects Left-over debris form comets and asteroids
Birth of the Solar System (Picture)
Size of the pLanets picture
Earth is 4,570,000,000 years old.
Geologic Time (A Timeline)
(MA)Millions of years ago
Lesson 2: The History of the Earth
Origin of the Universe:
The Universe began about 14.4 Billion years ago.
The Big Bang Theory states that in the beginning, the
universe was all in one place. All of its matter and
energy was squished into an infinitely small point called
a Singularity. Then, It exploded.
After about 10 Billion years after that, our solar system
began to form.
Birth of the Solar System:
The Nebular Hypothesis is the currently accepted
argument about how a solar system can form. We have
discovered over two hundred planets orbiting other
stars.
A large gas cloud(nebula) begins to condense. Most of
the mass is in the center, there is turbulence in the
outer parts.
Pictures from the Hubble Space Telescope show
newborn stars emerging from dense, compact pockets
of interstellar gas called evaporating gaseous globules
Picture
Gravitational attraction causes the mass of gas and dust
to slowly contract and it begins to rotate The dust and
matter slowly falls towards the center
4570 MA – Sun and Accretionary disk formed
4560 MA – Planetisimals accreted; accretion of earth
has begun.
4510 MA– Moon has been formed
4470 MA – Earth Accretion core formation,
differentiation completed
4400 MA = Oldest mineral Grain
4000 MA – End of heavy bombardment, oldest
continental rocks.
3800 MA – Earliest evidence of surface liquid water
3500 MA – Earliest evidence of Life
2500 MA – Major Phase of continent formation
completed
2450 – 2200 MA – Buildup of oxygen in atmosphere
2200 MA – Nucleus-bearing cells developed
700 MA – Ice covered Earth? (Dirty Ice Balls or asteroids
and comets)
565 MA – Worldwide distribution of multicellular
organisms
545 – 530 MA – Evolutionary “Big Bang”
439 MA – Mass Extinction
420 MA – Earliest land animals
364, 250, & 208 MA – Mass Extinction
125 MA – Earliest flowering plants
65 MA – Mass Extinction
5 MA – First Hominids
0.12 MA – First Appearance of our species, Homo
sapiens sapiens.
Formation of the Moon (Picture)
The Giant Impact Hypothesis predicts that around 50
million years after the initial creation of Earth, a planet
about the size of Mars collided with Earth. A
considerable amount of material was blown off into
space, but most fell back onto the Earth
Part of the material from the collision remained in orbit
around the Earth By the process collision and accretion,
this orbiting material coalesced into the Moon The early
Moon orbited very close to the Earth
Three Major factors that cause the heating and
melting of the Earth’s Interior:
1. Collisions – Transfer of kinetic energy into heat
2. Compression
3. Radioactivity or elements
Global chemical differential, the heavier elements,
including the melted iron, began to sink down into the
core of the Earth, while the lighter elements such as
oxygen and silica floated up towards the surface.
This global chemical differential was completed by
about 4.3 billion years ago, and the Earth had
developed a inner and outer core, a mantle and crust
Note that oxygen (O2) gas is not created by volcanic
eruptions
Creating the ocean
It is hypothesized that water vapor escaping from the
interior of the Earth via countless volcanic eruptions
created the oceans (this took hundreds of millions of
years)
Astronomers also hypothesize that comets impacting
the Earth were a major source of water that contributed
to creation of the oceans Remember, that comets are
best described as “dirty ice balls”
The earliest evidence of surface water on Earth dates
back about 3.8 billion years
Geologic time
the Earth is thought to have had a thin atmosphere
composed primarily of helium (He) and hydrogen (H)
gases
4570 million of years ago(ma)- sun and accretionary
disk formed
4560(ma)- planetesimals accreted; earth acceretion
begun
4510 (ma)- moon formed
4470 (ma)- earth accretion core formation and
differentiation completed
4400 (ma)- oldest general grain
4000 ma- end of heavy bombardment: oldest
continental rocks
3800 (ma)- earliest evidence for liquid water
3500(ma)- earliest evidence for life
2500 (ma)- major phase of continental formation
completed
2450-2200 (ma)- buildup of oxygen in atmosphere
2200 (ma)-nucleus-bearing cells developed
700 (ma)- ice covered earth?
565 (ma)- worldwide distribution of multicellular
organisms
545-530 (ma)-evolutionary ”big bang”
439 (ma)- mass extinction
420 (ma)- earliest land animals
364 (ma)-mass extinction
250 (ma)- mass extinction
208 (ma)- mass extinction
125 (ma)- earliest flowering plants
65 (ma)- mass extinction
5 (ma)- first hominids
0.12 (ma)- first appearance of our species(homo
sapiens)
These would include:
A billion Year Old Earth
Chemical composition of the earth
Whole Earth:
Crust:
Fe+O+Si+Mg = 93%
Si+O+Al = 82%
Lithosphere: strong, rocky outer shell of the solid Earth
including all the crust and the upper part of the mantle
to a depth of ~100 km (forms the plates)
Asthenosphere: weak,ductile layer of the mantle
beneath the lithosphere; deforms to accommodate the
motions of the overlying plates
Deep Mantle: mantle beneath the asthenosphere (~400
to 2900 km in depth)
Outer core: liquid shell composed of mostly iron
Inner core: innermost sphere composed primarily of
solid iron
Continents: Formed from solidified magma that floated
up from the Mantle
Oceans and Atmosphere: Fluid and gaseous outer
layers believed to have been created by out-gassing of
gases and fluids from volcanic eruptions (in a process
called volatile transfer)
The evolving atmosphere

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Water vapor (H2O)
Sulfur dioxide (SO2)
Hydrogen sulfide (H2S)
Carbon dioxide (CO2)
Carbon Monoxide (CO)
Ammonia (NH3)
Methane (CH4)
By 3.5 billion years ago, when the Earth was abillion
years old, it had a thick atmosphere composed of CO2,
methane, water vapor and other volcanic gases
By human standards this early atmosphere was very
poisonous
It contained almost no oxygen
Remember, today our atmosphere is 21% oxygen
By 3.5 billion years ago, the Earth also had extensive
oceans and seas of salt water, which contained many
dissolved elements, such as iron
But most important, by 3.5 billion years ago, there was
life on Earth


The Continents
By 2.5 billion years ago, the continents had been
formed The density of the continental crust (2.8
gr/cm3) is lighter that the crust found on ocean
bottoms (3.2 gr/cm3), so the continents rise above the
ocean floor A question that remains unanswered is,
when did plate tectonics start?
Is Earth Located in Habitable Zone?


LESSON 3: Discovery of a new Planet
Galactic Neighborhood


Galactic environment impacts habitability
milky Way galaxy’s edge is a life-favorable spot
-Not near active gamma ray source
-Not near galactic center with high star density
and ionizing radiation
-Loneliness in galaxy is helpful for life


Spectral class indicates photospheric
temperature
“HabStars” spectral range
-Early F
-G
- Mid-K
- 7000K to 4000K


Emit high-frequency UV radiation to trigger
atmospheric ozone formation
Emits not so much that ionization destroys life
Spectral Class of “Sun”





Earth rotates around the star, the “Sun”
Sun
-G2 star
-~6,000K
Sun is in “Habstar” range!
Ozone can form in atmosphere
Ionization is not deadly for life



All stars change luminosity
Stars vary in stability... stars that fluctuate
luminosity violently are poor candidates for
hosting life
The Sun is relatively stable!
- Solar variation is ~.1% over 11- year cycle
-Slight variations dramatically impact Earth
-Little Ice Age – decline in Sun’s luminosity
Terrestrial
-Silicate rocks
-Rocks not accreted to gaseous outer layers
Gas Giants = no life
- No surface
-Enormous Gravity
-Satellites are good candidates, however
Composition of Earth?

Earth is a terrestrial planet, not a gas giant
Mass of Planets need to be Just Right for Life

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Low Mass
Bad news for life
Lesser gravity – difficult for atmosphere
retention
Smaller planets lose energy from formation
quickly
geologically dead
Approximately 0.3 Earth masses needed to
sustain life
Mass of Earth

Low Stellar Variation?


Yes!
Earth is located within the expected shell of
distance in which liquid water can be on the
surface of the planet
Pictures of the planet show liquid water
covering a large portion of the Earth’s surface
Planet Characteristics that Support Life
Spectral Class of Star Needed for Life:

Habitable Zone
Theoretical shell around a star where any planet
present would have liquid water on its surface
HZ range should not vary over time
-Stars increase luminosity as they age
- If this happens too quickly (super-massive
star), planets are only in window for life for
short amount of time
-Lowers time to develop life
High Mass
-Earth is largest by mass and density of
terrestrial bodies in the Solar System
-Large enough for molten core (heat engine)
-Large enough for atmosphere through gravity
-Large enough for liquid outer core and metal
inner core (magnetic field)
Magnetic Fields and Life



Planets need protection from solar wind
Solar wind- stream of charged particles from
stars consisting of electrons and protons
Planet must have molten metal interior
Does Earth have a Magnetic Field?



Yes!
Earth has solid metal core with liquid outer
core, causing magnetic field
Protects the Earth from solar wind
Atmosphere and Life

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Is Earth’s Orbit Suitable?
 Yes!
 Earth’s Orbit
 Almost circular
 E < .02
Atmosphere – layer of gases that surround a
material body of sufficient mass
Held by gravity
Helps regulate temperature
Protects planet from meteors and radiation
Composition favors life (oxygen and carbon
dioxide)
Life-Supporting Rotation

Does Earth have an Atmosphere?




Yes!
Earth’s atmosphere is made up of
-Nitrogen (78%)
-Oxygen (20.9%)
-Argon (.93%)
-Carbon Dioxide (.0390%)
This composition could support life
Atmosphere absorbs/reflects harmful radiation
-Visible and Radio reach surface
Composition of Planets

Four elements vital for life
1. Carbon
2. Hydrogen
3. Oxygen
4. Nitrogen
Earth’s Rotation?

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Element oxygen alone found in Earth’s crust...
However, other life elements are found in
atmosphere and water
Make amino acids (building blocks of protein)
Comets and out gassing from volcanoes brought
these elements
Tectonic Activity of Planet
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Supply surface with life-sustaining material
Supply atmosphere with temperature
moderators(CO2)
Recycles important chemicals/materials
Helps increase environmental complexity
Earth is tectonically active
Life-Supporting Orbits


Stability is critical
Eccentricity
-Greater e, greater temperature fluctuation
-Living organisms can only withstand certain
fluctuations
-Complex organisms have greater temperature
sensitivity
Earth’s tilt varies between 21.5 and 24.5
degrees every 41,000 years
Day is only 24 hours
Moon plays crucial role
-Moderates Earth’s climate by stabilizing axial
tilt
LESSON 4:
Earth’s atmosphere


Earth’s Composition?


Rotation around axis at tilt
-Planet should have moderate seasons or
biospheric dynamism will disappear
-Without tilt, planet would be colder (warm
weather could not move pole ward)
-Should not be radically tilted because seasons
would be extreme
-Speed of Rotation
-Should be relatively quick so day-night cycle is
not too long (temperature differences if long
days/nights)
Earth’s atmosphere is a layer of gases
surrounding the planet.
The Earth is surrounded by a blanket of air,
which we call the atmosphere. It reaches over
560 kilometers from the surface of the Earth.
Atmosphere:
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Absorbs the energy from the Sun,
Recycles water and other chemicals,
protects us from high-energy radiation and the
frigid vacuum of space.
The atmosphere protects and supports life.
Earth Has 4 main systems that interact:

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The Atmosphere
The Hydrosphere
-All of Earth’s water, whether in the
atmosphere, glaciers, oceans, lakes or rivers.
The Biosphere
The Geosphere


itself has been around pretty much as long as
the earth has!
When the first fish swam in the ocean, your
glass of water was part of that ocean. When the
Brontosaurus walked through lakes feeding on
plants, your glass of water was part of those
lakes
When kings and princesses, knights and squires
took a drink from their wells, your glass of
water was part of those wells. And you thought
your parents were OLD
Evaporation:

Evaporation is when the sun heats up water
in rivers or lakes or the ocean and turns it into
vapor or steam. The water vapor or steam
leaves the river, lake or ocean and goes into the
air.
Do plants Well, sort of.... sweat?
Hydrosphere

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
Water on Earth is a unique feature that clearly
distinguishes our "Blue Planet" from others in
the solar system.
Not a drop of liquid water can be found
anywhere else in the solar system. Earth has
just the right mass, the right chemical
composition, the right atmosphere, and is the
right distance from the Sun that permits water
to exist mainly as a liquid.
Water is the universal solvent and the basis of
all life on our Planet.
The water Cycle

Water, which covers the majority of the Earth’s
surface (the hydrosphere), circulates through
the crust, oceans, and atmosphere in what is
known as the water cycle.
Water Cycle—water is in constant motion

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The Sun provides water cycle’s energy
Water on the surface absorbs heat and
evaporates, entering the atmosphere
Condensation—water vapor changes back into
liquid.
Clouds of water become heavy and water falls
to Earth as precipitation.
The cycle repeats itself continuously.
The Water Cycle

Run and get a glass of water and put it on the
table next to you. Take a good long look at the
water.
Now -- can you guess how old it is?

The water in your glass may have fallen from
the sky as rain just last week, but the water

people perspire (sweat) and plants transpire.
Transpiration is the process by which plants lose
water out of their leaves. Transpiration gives
evaporation a bit of a hand in getting the water
vapor back up into the air.
Condensation:


Water vapor in the air gets cold and changes
back into liquid, forming clouds. This is called
condensation.
You can see the same sort of thing at home...
pour a glass of cold water on a hot day and
watch what happens. Water forms on the
outside of the glass. That water didn't somehow
leak through the glass! It actually came from
the air. Water vapor in the warm air, turns back
into liquid when it touches the cold glass.
Precipitation:

Precipitation occurs when so much water
has condensed that the air cannot hold it
anymore. The clouds get heavy and water
falls back to the earth in the form of rain,
hail, sleet or snow.
Collection:
When water falls back to earth as
precipitation, it may fall back in the oceans,
lakes or rivers or it may end up on land.
When it ends up on land, it will either soak
into the earth and become part of the
“ground water” that plants and animals use
to drink or it may run over the soil and
collect in the oceans, lakes or river where
the cycle starts
Earth’s atmosphere

Earth’s atmosphere is made of a mixture of
gases called air.
-Nitrogen gas makes up about 78% of
Earth’s atmosphere.
-The second most abundant gas is
oxygen, which makes up 21% of
Earth’s atmosphere.
- The third Argon (Ar, 0.9%).
- Carbon Dioxide (CO2, 0.03%).
Composition of the Atmosphere
The atmosphere is comprised of a variety of gases:


Major Constituents (99%):
-Nitrogen (N): 78%
-Oxygen (O2): 21%
Trace Constituents:
-Argon (Ar), about 0.9%
-Water vapor (H2O), up to 10000 ppmv
-Carbon dioxide (CO2), 350 ppmv
-Ozone (O3), near zero at the surface, up to
10 ppmv in the stratosphere
-Methane (CH4), 1.7 ppmv and others.....
ppmv = “parts per million by volume”
Nitrogen cycle


Nitrogen is important to protein which is
found in the body tissues of all living things.
Nitrogen is cycled through the soil and into
plants and finally when living things die and
decay.
Pressure in the atmosphere



Atmospheric pressure is the force per unit are
exerted into a surface by the weight of air
above that surface in the atmosphere of Earth.
The gas molecules closest to Earth’s surface are
packed together very closely.
This means pressure is lower the higher up you
go into the atmosphere.
Pressure in the atmosphere


At sea level, the weight of the column of air
above a person is about 9,800 Newtons (2,200
pounds)
This is equal to the weight of a small car.
Measuring Pressure



A barometer is an instrument that measures
atmospheric pressure.
Long ago, mercury barometers were used
Since mercury is a poisonous liquid, aneroid
barometers are used today.
Layers of Atmosphere
The atmosphere has four layers

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Thermosphere
Mesosphere
Stratosphere
Troposphere
Troposphere
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Lowest and thinnest layer
16 km at equator, 8 km at poles
90% of the atmosphere’s mass
Temperature decreases with altitude
6°C per kilometer
Top of troposphere averages –50°C
-Where weather occurs
-Boundary between the troposphere, and the
stratosphere is called the tropopause.
Stratosphere

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Extends from 10 km to 50 km above the ground
Less dense (less water vapor)
Temperature increases with altitude
Almost no weather occurrence
Contains high level of ozone
Ozone layer
Upper boundary is called stratopause.
Mesosphere




Extends to almost 80 km high
Gases are less dense.
Temperature decreases as altitude increases.
Gases in this layer absorb very little UV
radiation.
Thermosphere

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Above the mesosphere and extends to almost
600 km high
Temperature increases with altitude
Readily absorbs solar radiation
Temperature can go as high as 1,500°C
Reflects radio waves
The four layers of theatmosphere include:
1. the troposphere, where we live;
2. the stratosphere, which contains the ozone layer;
3. the mesosphere, where meteors burn; and
4. the thermosphere, where satellites orbit Earth.


The exosphere begins at about 500 kilometers
above Earth and does not have a specific outer
limit.
Satellites orbit Earth in the exosphere.
The exosphere and ionosphere


Communication on Earth depends on satellites.
Satellites transmit information used for
television shows, radio broadcasts, data and
photos used in weather reports, and long
distance telephone calls.

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
The heated surface emits infrared light.
The majority of Earth’s atmosphere (N2 and O2)
are not good greenhouse gas.
The small amount of greenhouse gases (H2O,
CO2) traps (absorb and re-emit) the infrared
radiation, increasing the temperature of the
atmosphere...
Ozone layer

In the 1970s, scientists noticed that the ozone
layer in the stratosphere above Antarctica was
thinning.
Chlorofluorocarbons & the ozone layer





A group of chemicals called chlorofluorocarbons
(or CFCs) were once commonly used in air
conditioners, in aerosol spray cans, and for
cleaning machine parts.
In the London Agreement of 1991, more than
90 countries banned the production and
use of CFCs except for limited medical uses.
The ozone layer absorbs the Sun’s high-energy
ultraviolet (UV) radiation and protects the
Earth.
In the stratosphere, the CFCs break down and
release chlorine.
The chlorine reacts with ozone molecules,
which normally block incoming ultraviolet
radiation.
Acid rain occurs when oxides of sulfur and oxides of
nitrogen are emitted into the atmosphere, undergo
chemical transformations and are absorbed by water
droplets in clouds.
Layers of the earth


Composition
• Composition= what it’s made of
Effects of Acid Rain



If we could take a chunk out of the Earth, we
would see that it is made up of different layers.
Earth is made up of 3 main layers
– Crust
– Mantle
– Core
Physical Properties and
• Physical properties= characteristic that is
unique and helps to identify the substance
(temp, size, shape, color)
Acidification of bodies of water
Damage of vegetation
Damage to building materials, statues, etc.
• Example: Chocolate Chip Cookies
-Composition- flour, eggs, sugar, chocolate
chips, baking powder, butter
-Properties- round, rough, sweet, tan and black,
hot, lumpy,
CRUST
The Greenhouse Effect on Earth
Earth’s atmosphere is slightly warmer than what it
should be due to direct solar heating because of a mild
case of greenhouse effect...

The ground is heated by visible and (some)
infrared light from the Sun.
– Physical Properties:
• outermost layer
• thinnest layer (5-70km thick)
• Surface temperature
• 1% of Earth’s mass
• where we live
• touches the atmosphere
– Composition:
• consists of loose rocks
& soil
2 Types of Crust:
•
Continental Crust:dry land, granite ess dense

Oceanic Crust: ocean floor,Basalt, thinner
than cont. crust
Mesosphere Bottom Mantle
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strong, lower part of the mantle
layer between asthenosphere and core
The Core Outer and Inner
• The core is divided into two parts
MANTLE
–Physical Properties:
• thickest layer (2900km thick)
• 1600-4000 F
• 66% of earth’s mass
• flowing
– Composition:
• Molten rock
–Magma
– Outer Core:
• Liquid iron and nickel that’s spinning
– Inner Core:
• Solid iron and nickel
• Solid because of all the pressure of the rest of the
Earth surrounding it.
How do we know?
CORE
– Physical properties:
• HOT! 4000-8000 F
• Very dense
• High pressure
• 4000 miles from surface
• 33% of Earth’s mass
• About the same size as
Mars
– Composition:
• Iron and Nickel (metals)
What have you noticed about temperature and
pressure?
• As you get deeper inside the Earth,
temperature Increases
• As you get deeper inside the Earth, pressure
Increases
The 3 main layers of the Earth can be divided further by
the way they “act” within the Earth and by their
different physical properties.
Lithosphere
Crust and upper Mantle
• outermost layer – includes crust and upper mantle
• rigid
• divided into pieces or tectonic plates
• Rocks and soil
Asthenosphere Middle Mantle
• composed of solid flowing rock
• layer on which pieces of lithosphere move on top
(solid rock that flows)
– Think of it like caramel
• Seismic waves produced by earthquakes travel at
different speeds through solid rock and liquids