Group 3A: The Boron Group
 Boron
 Aluminum
 Gallium
The Boron Group
Boron
Gallium
Aluminum
The Boron Group
• Group 3A elements are always found combined with
other elements in nature.
• Based on the group number you would expect for
group 3A elements to lose 3 valence electrons to
form ions with 3+ charge.
• Boron, Aluminum, Gallium, and Indium form such
ions, but Thallium does not.
• Thallium is the most metallic member of the group
with properties similar to those of alkali metals.
• Gallium and indium can form ions with a 1+ charge.
Boron
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Although group 3A is named for
metalloid boron, as with other groups,
the lightest member is the least
representative.
Boron has more in common with silicon
in group 4A than with the metallic
members of group 3A.
The main source of boron is a complex
compound of boron called borax.
Borax is used as a cleaning agent and
as fire proof insulation.
Boric acid, another compound of boron
is used as a disinfectant and an
eyewash.
A form of boron nitride is the second
hardest known material ; only diamond
is harder.
These materials are classified as
superabrasives.
Aluminum
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Aluminum is the most
abundant metal and the third
most abundant element in
earth’s crust.
Aluminum oxide is the major
compound in bauxite. It is used
as an abrasive, to strengthen
ceramics, and in heat resistant
fabrics.
The compound aluminum
sulfate, known as alum, is
used in antiperspirants and to
remove suspended particles
during water purification.
Gallium
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Gallium can literally melt in your hand.
A compound of gallium and arsenic called gallium arsenide produces an
electric current when it absorbs light.
This property makes gallium arsenide ideal for the semiconductor chips
used in light powered calculators and solar panels.
Scientist are using a compound of gallium and nitrogen, gallium nitride, to
develop lasers that emit blue rather than red light.
Using the shorter wavelengths of blue light would triple the storage capacity
of a DVD.
Metical devices for detecting cancer cells could be less expensive if they
use low cost, blue light lasers.
Quiz!!
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What is the main source of Boron?
Borax
What is it used for?
Cleaning and fireproof insulation
What is the most abundant metal?
Aluminum
What is the compound aluminum sulfate used in?
Antiperspirants
What is a compound of gallium and nitrogen, and
gallium and nitride used to make?
Lasers that emit blue light