SC5v - METALS

Question 1

physical properties of transition metals (5)

Answer 1

• high melting points
• hard and strong
• high density
• good conductors of heat and electricity
• malleable and ductile

Question 2

chemical properties of transition metals

Answer 2

• less reactive than group 1 and 2 metals
• can act as catalysts
• form coloured compounds

Question 3

corrosion of iron is called ______

Answer 3

rusting

Question 4

rusting requires ______ and ______

Answer 4

oxygen and water
iron + oxygen + water -> hydrated iron oxide

Question 5

tarnish definition

Answer 5

when a metal forms a protective layer of metal oxide which stops the metal from corroding further

Question 6

methods to prevent rusting (2)

Answer 6

• coating with paint, plastic, coat, oil or grease; keeps oxygen and water away from the metal
• sacrificial protection; include a more reactive metal which will corrode in preference

Question 7

electroplating definition

Answer 7

coating a thin layer of one metal on top of another metal

Question 8

uses for electroplating (3)

Answer 8

• to coat jewellery with silver or gold
• to stop the base metal corroding
• to improve the conductivity of the metal

Question 9

describe the method for electroplating

Answer 9

• electrolysis
• the anode is made of copper
• the cathode is the metal object which is being coated

Question 10

alloy definition

Answer 10

a mixture of metals

Question 11

steel is a mixture of ______ and ______

Answer 11

metal and carbon

Question 12

alloys are used because ________

Answer 12

they have improved properties over pure metals

Question 13

pure metals are soft because the atoms are _______

Answer 13

the atoms are regularly arranged and can easily slide over each other

Question 14

alloys are harder and stronger than pure metals because the atoms _______

Answer 14

the atoms are of different sizes which disturbs the regular structure and means the layers can’t slide over each other