Metals

Question 1

Describe the general physical properties of metals

Answer 1

• High melting & boiling points
• High density
• Ductile & malleable
• Good conductors of heat & electricity
• shiny silver grey appearance
  -sonorous

Question 2

Describe an alloy

Answer 2

A mixture of a metal with other element(s)
Eg; brass - copper + zinc
steel - iron + carbon

Question 3

Explain, using ideas of bonding & structure why alloys have a different physical property than pure metals

Answer 3

In the structure of a pure metal, the atoms are all equal sizes & orderly arranged. When a force is applied, layers of atoms can slide over each other easily.
In the structure of an alloy, atoms of different sizes disrupts the orderly arrangement of the atoms. Hence, when a force is applied, layers of atoms cannot slide over each other easily.
This is why alloys are generally harder/stronger than pure metals.

Question 4

What is metallic bonding?

Answer 4

It is the electrostatic forces of attraction between the positively changed metal ions and the sea of delocalised mobile negatively charged electrons in the same structure.

Question 5

Explain, using ideas of bonding and structure why metals can conduct electricity

Answer 5

The sea of delocalised mobile electrons in the structure enables electrons to flow through the structure

Question 6

Explain, using ideas of bonding & structure why metals can have high melting points

Answer 6

large amount of energy is needed to overcome the strong electrostatic forces of attraction between the positively charged metal ions and the sea of delocalised mobile negatively changed electrons in the structure