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Earth’s Mineral Resources
Unit 2 Sect B
Environmental Chemistry
Coin-Design Competition
• One requirement for the new coin is to
specify the coin’s material/composition
• We have studied the elements
• Where are the elements located on Earth?
• First a little background about the earth’s
structure
Cross Section of the Earth
Cross Section of Earth
• Earth can be divided into 3 main layers
based on the materials that make up those
layers
– _____
• Continental
• Oceanic
– _______
• Lithosphere
• Asthenosphere
• Mesosphere
-- _______
Inner
Outer
Earth’s Crust
• Rocky outer layer of earth is the crust
• Thin compared to other layers
• Mostly made of ___________ (elements
silicon and oxygen), aluminum, iron,
calcium
Two Types of Earth Crust
• Continental crust: the rock that makes up
the earth’s continents
– Averages 40 km thick
• Oceanic crust: rock that makes up ocean
floor
– Averages 7 km thick
The Mantle
• Earth’s mantle: thick layer of solid rock
below earth’s crust
– About 2850 km thick
– Mostly made of _____________
– More dense than crust
• Pressure and temperature increases as
you get deep inside the earth
Three Layers of Mantle
• Lithosphere: ____________ part of mantle
– Cool, rigid rock
• Asthenosphere: middle part of mantle
– Softer, weak layer, flows like taffy
• Mesosphere: bottom part of mantle
– Strong and stiff rock layer
The Core
• The core is a large sphere of metal that
occupies Earth’s center
– Mostly made of _______(allows for earth’s
magnetic field)
– Very high pressure! Almost 3.6 million times
that of earth’s surface
– Temperature: about 5500oC
• Outer core: liquid metal (high temp)
• Inner core: solid metal (high pressure)
Study Buddy Review
• What are the three main layers
of the Earth?
• What happens to the
temperature and the pressure as
you descend into the Earth?
• Which metal is in the core of the
Earth? Why is that important?
Sources and Uses of Metals
Sources of Elements on Earth
• Atmosphere: _______________________
• Hydrosphere: water components of the
earth’s surface
• Lithosphere: solid part of earth
Sources of Metals
• Ore: naturally occurring ______________
______________________ and from which
it is profitable to extract a metal or other
material.
• Minerals: naturally occurring solid
compounds containing the element of
interest
Study Buddy Review
• What is the atmosphere?
• What are minerals?
• What is a metal ore?
Metal Properties and Uses
Historic Use of Metals
• Gold and silver were probably the first
metals used by humans.
– Found as free elements (not in
ores/compounds)
– Decorative
– __________________
Historic Use of Metals
• Copper used ~10,000 years
– Bronze (alloy of _________________)
developed about 3800 BC
– Alloy: mixture (solution) of different metals
• Iron metallurgy (extract iron from iron ore)
led to Iron Age ~3000 BC
Study Buddy Review
• Why were the elements gold and silver
probably the first used by humans?
• What is bronze?
• When was the Iron Age?
Activity Series
Coinage Metals
• Group 11 (Cu, Ag, Au) are sometimes called
the coinage metals
– _______________________________________
– _______________________________________
• What results did you get for the reactivity of
silver in the lab?
Reactivity of Metals Lab
• In what order of reactivity did you place
the metals tested in lab?
– Reactivity means corrosion, formation of new
compound, creation of coating, etc.
• ________________________
• Is there an order of reactivities of metals in
nature?
Activity Series of Metals
• __________________________ metal elements
ranked in order of their chemical reactivity.
• Most reactive metals at the _____ of the list (Mg)
• Least reactive metals at the ___________ of the
list (Au)
• Most reactive metals have low reactive ion in
solutions (Mg2+)
• Least reactive metals have highly reactive ion in
solutions (Ag+)
How do Metals React?
• When metals react, they lose electrons
• When atoms lose electrons, they form
_______________ charges
• Process is called _________________
Mg (s)  Mg 2+ (aq) + 2 e• Where did the electrons go?
• Electrons flow to another substance
Substances That Accept Electrons
• Substances that ______electrons undergo
a process called _________________:
Cu 2+ (aq) + 2 e-  Cu (s)
Redox Reactions
• Oxidation reactions always accompany
reduction reactions
• Called _____________________
• OIL RIG
– Oxidation is losing electrons
– Reduction is gaining electrons
Redox Reactions
Cu 2+ (aq) + 2 e-  Cu (s)
Mg (s)  Mg 2+ (aq) + 2 eCu 2+ (aq) + Mg (s)  Cu (s)
• The number of electrons are always conserved
______________________________________
______________________________________
• The flow of electrons can be used to create
electrical energy.
Summary of Oxidation and
Reduction
Oxidation
• Lose electrons
• e- appear on right side of
arrow in equation
• Charge number becomes
more positive
Reduction
• Gain electrons
• e- appear on left side of
arrow in equation
• Charge number becomes
more negative
Oxidizing and Reducing Agents
• Oxidizing Agents: are the substances that
are ____________(Mg2+)
• Reducing agents: are the substances that
are ____________(Cu)
Other Methods for Isolating Metals
• Electrometallurgy: involving the use of
________________________ to supply
electrons to metal ions and reducing them
• Pyrometallurgy: the treatment of metals and their
ores by _________________
– Oldest ore-processing method
• Hydrometallurgy: obtaining metals from their
ions by treatment of ores and other metalcontaining materials by
______________________________________
Study Buddy Review
•
•
•
•
What is the activity series of metals?
What is oxidation?
What is reduction?
What is an oxidizing agent?