Transcript Elements on Earth

The Elements
On Our Earth
Elements in the Atmosphere
• Our atmosphere contains many elements
that we need in order to survive…
– Nitrogen (N) gas in the atmosphere consists
of N2 molecules (it is a diatomic molecule).
– Oxygen (O) is found as O2 molecules.
– Argon is found as a single, uncombined Ar
atom.
– Carbon Dioxide is released by us into the
atmosphere as CO2.
Elements on the Earth
• Our hydrosphere consists of all the water
that occurs at the earth’s surface.
– The chemical formula for water is H2O.
Elements in the earth’s Crust
• The earth’s crust contains many elements
such as Oxygen (O2), Silicon (Si),
Aluminum (Al), Iron (Fe) and others!
• Oxygen is the most abundant element. It is
also very reactive.
• Oxygen reacts with other elements for
form solid mineral compounds (ie. sand)
Reactivity
• How strongly an elements reacts with
other elements is an important chemical
property called reactivity
Other elements
• Metals
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All metals have certain properties in common
Metals conduct electricity and heat
Malleable and ductile
Solid state at room temperature (except mercury)
Shiny in appearance
Ex. Tin, Aluminium, Iron
• Non Metals
• Have very different properties than metals
• Can be gases or solids (only 1 liquid – bromine) at
room temperature
• Not shiny
• Poor conductors of heat and electricity
• Brittle, Non-ductile
• Ex. Hydrogen, Carbon, Sulfur
• Metalloids
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Have properties of both metals and non-metals
Solids at room temperature
Can be shiny or dull
May or may not conduct electricity
Poor conductors of heat
Brittle and non-ductile
Ex. Silicon, Boron, Arsenic
Extraction of Metals
• Most metals are reactive and have to be
contained in other compounds.
• These metals are mostly found in minerals
• A mineral is a solid pure substance that
occurs naturally in the earth’s crust
• Mineral deposits are found in ores in the
earth’s crust
• The minerals have to be extracted from
the earth
Extraction of Metals
• When the ore is collected, the mineral
goes through a process of concentration
(to collect as much mineral as possible)
• Once in mineral form, a process called
decomposition allows the metal to be
extracted and the excess unwanted
materials are discarded