Chapter 8 Chemistry(8.1)

 Alloy is a mixture of two or more element
 The main element is metal

Alloy:
 Shiny
 Resistant to corrosion
 Hard
Pure Metal:
 Dull
 Easily corroded
 Less Hard

 A pure metal is made up of one type of
atom that is of the same size and
arranged in an orderly arrangement.
When force is applied the layers of
atoms in the metal easily slide over each
other.

 Pure metals are also malleable and it’s
shape can be easily changed. There are
empty spaces between the atoms in a
pure metal. When force is applied, the
layer of atoms in a metal will slide to fill
the empty spaces and form a new
structure.



Bronze Duralumin Brass

• 90% Copper • 93% Aluminium • 70% Copper
• 10% Tin • 3% Copper • 30% Zinc
• 3% Magnesium
• Stronger than • 1%Manganese • Stronger than
pure copper pure copper
• Stronger than
• Does not rust pure • Does not rust
• Shiny aluminium • Shiny
• Medals • Musical
• Monuments • Does not rust
• Trophies • Body of instruments
• Doorknobs
Aeroplane • Key
• Electric

Cables
• Racing

Bicycle

Steel Stainless Steel Pewter

• 98% Iron • 73% Iron • 95% Tin
• 10% Tin • 18% Chromium • 3.5% Antinomy
• Also known as • 8% Nickel • 1.5% Coppper
• Stronger than • Stronger than
carbon steel
• Stronger and pure iron pure tin
• Resistant to • Does not rust
harder • Shiny
• Malleable corrosion • Decorative
• There are three • Cutlery
• Sinks ornaments
types of steel, • Surgical • Trophies
which are low- • Souveniers
carbon steel, instruments
average-carbon
steel and high-
carbon steel
• Structure of
buildings
• Railway tracks
• Body of cars

 An alloy is formed when foreign atoms
are mixed with the pure metal. These
foreign atoms are different in size
compared to the atoms in pure metal.
Hence the orderly arrangement of atoms
in a pure metal is disrupted. This makes it
difficult for the layers of atoms in an alloy
to slide over each other when force is
applied.