Chemical bonding 4.5

Question 1

Metallic bond

Answer 1

Electrostatic attraction between a lattice of positive ions and delocalized electrons.

Question 2

Factors affecting the strength of metallic bond

Answer 2

1) The charge of the ions

2) The radius of the metal ion

Question 3

Properties of metals

Answer 3

1) Shiny
2) Ductile (can be drawn into wires)
3) High MP’s and BP’s (e.g Iron)
4) Good conductor of heat electricity
5) Malleable ( can be bent )
6) Delocalized electrons conduct heat, electricity, reflect light therefore metals appear shiny.

Question 4

What are Alloys ?

Answer 4

Material composed of 2 or more metals or a metal and a non-metal.

Question 5

How can metals forms alloys ?

Answer 5

1) Bonding in metals is non-directional
2) Force of attraction between the positive metal ions and the delocalised electrons acts in every direction around the fixed metal ions

Question 6

Types of alloys

Answer 6

1) Substitutional alloys : atoms of 1 metal are substituted by atoms of another metals
2) Interstitial alloys : Different metals occupies holes in the lattice structure

Question 7

Properties of alloys

Answer 7

1) Different than the metals they are made of
2) Harder , less malleable
3) Stronger, greater tensile strength
4) Makes it harder for the layers to slide over each other.

Question 8

Steel

Answer 8

Iron+ Carbon

1) High tensile strength
2) Used in construction

Question 9

Stainless steel

Answer 9

Iron+nickel+Chromium

1) resistant to corrosion
2) Cutlery

Question 10

Brass

Answer 10

Copper+Zinc

1) Pipes, musical instruments

Question 11

Bronze

Answer 11

Copper+ tin

1) used in statues, medals, coins, tools

Question 12

Pewter

Answer 12

Tin+ Copper+antimony

1) Decorative ornaments

Question 13

Solder

Answer 13

Lead+ Tin

1) Low mp
2) use to join metals in electrical circuits

Question 14

Nichrome

Answer 14

Nickel + Chromium

1) Used in heating elements