Post by Admin on Nov 24, 2016 10:06:06 GMT
Properties of Metals
Usually solids(except for mercury)
Malleable - they can be hammered or pressed into shape
Good conductors of heat and electricity
Lustrous (shiny) appearance
Ductile - they can be stretched out into thin wires without breaking
Usually very dense
High melting points
Usually corrode
Corrosion
Corrosion is when a metal reacts with oxygen to form an oxide
Rusting is the corrosion of iron or steel.
Rusting requires water and oxygen.
Corrosion can be prevented by painting, chrome plating, galvanising or greasing.
Alloys
An alloy is a mixture of two or more metals.
Bronze is a mixture of copper and tin.
Steel is a mixture of iron and carbon.
Brass is a mixture of copper and zinc.
The Activity Series
The activity series is a list of metals in decreasing order of reactivity.
The order of reactivity (from most to least reactive) of the 4 metals on the Junior Cert course is: Calcium, Magnesium, Zinc, Copper.
Zinc reacts with hydrochloric acid to form zinc chloride and hydrogen.
Metals react with acids to give off hydrogen gas (H2).
e.g. Zn + 2HCL -> ZnCl2 + H2.
Usually solids(except for mercury)
Malleable - they can be hammered or pressed into shape
Good conductors of heat and electricity
Lustrous (shiny) appearance
Ductile - they can be stretched out into thin wires without breaking
Usually very dense
High melting points
Usually corrode
Corrosion
Corrosion is when a metal reacts with oxygen to form an oxide
Rusting is the corrosion of iron or steel.
Rusting requires water and oxygen.
Corrosion can be prevented by painting, chrome plating, galvanising or greasing.
Alloys
An alloy is a mixture of two or more metals.
Bronze is a mixture of copper and tin.
Steel is a mixture of iron and carbon.
Brass is a mixture of copper and zinc.
The Activity Series
The activity series is a list of metals in decreasing order of reactivity.
The order of reactivity (from most to least reactive) of the 4 metals on the Junior Cert course is: Calcium, Magnesium, Zinc, Copper.
Zinc reacts with hydrochloric acid to form zinc chloride and hydrogen.
Metals react with acids to give off hydrogen gas (H2).
e.g. Zn + 2HCL -> ZnCl2 + H2.