Earth Materials

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Earth Materials
O Griffiths Heolddu Comprehensive School
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Limestone
Limestone is a __________ rock made up of mainly
calcium carbonate. Its cheap and easy to
obtain. Some uses
1) Building materials limestone can be
quarried and cut into blocks to be used in
_______. However, it is badly affected by ____
____.
2) Glass making glass is made by mixing
limestone with _____ and soda
3) Cement making limestone can be roasted in
a rotary kiln to produce dry cement. Its then
mixed with sand and gravel to make _______.
Words sand, building, sedimentary, concrete,
acid rain
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Limestone
Words slaked, acidic, neutralise,
decomposition, carbon dioxide
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Formation of oil and gas
1) Layers of dead sea _____ settle on the seabed.
2) Layers of __________ rock build up on top.
3) The heat and ________ from these rocks, along
with the absence of ______, mean that oil and gas
are formed over ______ of years.
Words sedimentary, millions, oxygen, creatures,
pressure
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Hydrocarbons and crude oil
Crude oil is a mixture of a very large number of
HYDROCARBONS (compounds made up of carbon and
hydrogen). Some examples

• Longer chains mean
• Less ability to flow
• Less flammable
• Less volatile
• Higher boiling point

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Fractional distillation
Crude oil can be separated by fractional
distillation. The oil is evaporated and the
hydrocarbon chains of different lengths condense
at different temperatures
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Cracking
Shorter chain hydrocarbons are in greater demand
because they burn easier. They can be made from
long chain hydrocarbons by cracking
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Cracking
This is a THERMAL DECOMPOSITION reaction, with
clay used as a catalyst
Cracking is used to produce plastics such as
polymers and polyethanes. The waste products
from this reaction include carbon dioxide,
sulphur dioxide and water vapour. There are
three main environmental problems here

1. Carbon dioxide causes the _________ effect
2. Sulphur dioxide causes _____ _____
3. Plastics are not _____________

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Alkanes
Alkanes are SATURATED HYDROCARBONS. What does
this mean? HYDROCARBONS are molecules that are
made up of hydrogen and carbon atoms SATURATED
means that all of these atoms are held together
by single bonds, for example
Alkanes are fairly unreactive (but they do burn
well).
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Alkenes
Alkenes are different to alkanes they contain
DOUBLE COVALENT bonds. For example
This double bond means that alkenes have the
potential to join with other molecules this
make them REACTIVE. We can test for alkenes
because they turn bromine water colourless.
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Making Ethanol

• By reacting ethene with steam in the presence of
  a , ethanol can be produced.
• Ethanol is used

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Monomers and Polymers
Heres ethene again. Ethene is called a MONOMER
because it is just one small molecule. We can
use ethene to make plastics
Step 1 Break the double bond
Step 2 Add the molecules together
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Another way of drawing it
Instead of circles, lets use letters
General formula for addition polymerisation
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Polymers

• The properties of polymers depend on what they
  are made of and the conditions under which they
  are made.
• E.g. Slimes with different viscosities.
• List some uses of polymers.

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Problems with polymers

• Many are not . This means
  that they are not by . This
  can lead to problems with disposal. Such
  as
• -
• -
• -
• -
• -

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Evolution of the Earths Atmosphere
Present day atmosphere contains 78 nitrogen, 21
oxygen, 1 noble gases and about 0.03 CO2
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Evolution of the Earths Atmosphere
Some of the oxygen is converted into ozone. The
ozone layer blocks out harmful ultra-violet rays
which allows for the development of new life.
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Carbon dioxide in the atmosphere
The amount of CO2 in the atmosphere is affected
by 3 things
1) Geological activity moves carbonate rocks
deep into the Earth and they release ______
_______ into the atmosphere during volcanic
activity.
2) When fossil fuels are burned the carbon
contained in them reacts with _____ to form CO2.
3) Increased CO2 in the atmosphere causes a
reaction between it and _______. These reactions
produce two things INSOLUBLE CARBONATES (which
are deposited as ______) and SOLUBLE
HYDROGENCARBONATES (which ________ in the
seawater). These reactions do not remove ALL of
the new CO2 so the greenhouse effect is still
getting _______!
Words oxygen, seawater, carbon dioxide, worse,
dissolve, sediment
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The Structure of the Earth
The average density of the Earth is much higher
than the crust, so the inner core must be very
dense
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Tectonic theory
People once thought that the oceans and the
continents were formed by shrinkage from when the
Earth cooled down after being formed. Alfred
Wegener proposed something different. Consider
Africa and South America
These continents look like they fit together.
They also have similar rock patterns and fossil
records. These two pieces of evidence led me to
believe that there was once a single land mass.
This is my TECTONIC THEORY.
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Movement of the Lithosphere
The Earths LITHOSPHERE (i.e. the _______) is
split up into different sections called ________
plates
Words radioactive, crust, convection, tectonic,
year
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Tectonic theory

• The Evidence
• Some continents look like they used to fit
  together
• Similar rock patterns and fossil records

The Problems Wegener couldn't explain how
continental drift happened so nobody believed him

• The Answer
• Scientists discovered 50 years later that the
  Earth generates massive amounts of heat through
  radioactive decay in the core. This heat
  generated convection currents in the mantle
  causing the crust to move
• We also now know that the sea floor is spreading
  outwards from plate boundaries

Conclusion scientists now believe Wegeners
Tectonic Theory
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The Crust
Sedimentary rocks settle in layers. The oldest
rock is at the bottom.
Layers of sedimentary rock can be examined to
discover how they were formed. They are often
found folded or fractured
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Forming mountains
The formation of mountain ranges can be explained
by tectonic theory. Consider the Himalayas at
the top of India
The intense heat and pressure from this process
causes the rocks to change structure into
metamorphic rocks.
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Forming new crust
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Movements of the crust
When the lithosphere (crust) moves three things
can happen
1) Plates move past each other, causing
earthquakes
2) Plates move away from each other a
constructive plate margin. The gap is filled
with magma which cools to form basalt. This is
called sea floor spreading.
3) Plates move towards each other a
destructive plate margin. The less dense one
slides underneath (subduction) and partially
melts. This causes volcanoes and earthquakes.
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Evidence for sea floor spreading
Since the Earth was formed the north and south
poles have periodically ________ ____. When
tectonic plates move apart and _____ fills the
gap the iron particles in the magma orientate
themselves in line with the Earths ________
field. This means that the rock formed on the
sea floor contains a magnetic __________ of the
changing field
These magnetic patterns can be used to prove that
sea floor spreading does happen, and at a rate of
about 2cm per _____.
Words impression, magma, swapped over, magnetic,
year
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Predicting Catastrophe

• How easy is it to predict when an earthquake will
  happen or an volcano will erupt?

We can predict earthquakes are likely to
occur, but not they are likely to occur.
Volcanoes usually show before
they erupt. Therefore it is slightly easier to
predict when one might erupt.
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Group 0 The Noble gases
He
Ne
Ar
Kr
Xe
Rn







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Group 0 The Noble gases
Some facts







1) All of the noble gases have a full outer
shell, so they are very ______
2) They all have _____ melting and boiling points
3) They exist as single atoms rather then
_________ molecules

1. Helium is ________ then air and is used in
   balloons and airships (as well as for talking in
   a silly voice)

1. Argon is used in light bulbs (because it is so
   unreactive) and argon , krypton and ____ are used
   in fancy lights

Words neon, stable, low, diatomic, lighter
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The Periodic Table
H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Fe Ni Cu Zn Br Kr
Ag I Xe
Pt Au Hg

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The structure of the atom
Particle Relative Mass Relative Charge
Proton 1 1
Neutron 1 0
Electron 0 -1
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The structure of the atom
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Compounds
Compounds are different to elements. They
contain different atoms. Here are some examples
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Some simple compounds
Carbon dioxide, CO2
Water, H2O
Ethyne, C2H2