metals

Question 1

properties of metals

Answer 1

-shiny/ lustrous
-solid at rtp
-usually have high density
-strong
-can be bent/ malleable and stretched without breaking/ ductile
-high melting and boiling points (mercury and group 1 exceptions)
-good conductors of heat
-good conductors of electricity

Question 2

alloys

Answer 2

brass
-copper and zinc
-used in musical instruments, coins, hinges, electrical plugs

bronze
-copper and tin
-used in sculptures

mild steel
-iron and carbon
-used in bodies of cars

stainless steel
-iron, carbon, chromium and nickel
-used in cutlery, utensils, medical instruments

Question 3

reaction of metals with water

Answer 3

-reacts violently with cold water - potassium and sodium
-reacts readily with cold water - calcium
-reacts very slowly with cold water - magnesium and aluminium
-reacts violently with steam - hot magnesium
-reacts readily with steam - hot aluminium and zinc
-reacts slowly with steam - red-hot iron
-no observable reaction - lead, copper, silver and gold

Question 4

generalisation about reaction with water products

Answer 4

-when reacted with cold water, hydroxide is produced
-when reacted with steam, oxide is produced

Question 5

reaction of metals with dilute hydrochloric acid

Answer 5

-explosive reaction - potassium and sodium
-reacts vigorously - calcium
-reacts rapidly - magnesium and aluminium
note that aluminium forms oxide layer on its surface, preventing water or acid from direct contact with the metal
-reacts moderately fast - zinc
-reacts slowly - iron and lead
-based on reactions of metals with hydrochloric acid - hydrogen
-no observation reaction - copper, silver and gold

Question 6

extracted by electrolysis

Answer 6

-potassium, sodium, calcium, magnesium and aluminium

Question 7

extracted by reduction with carbon

Answer 7

-zinc, iron, lead, copper and silver

Question 8

displacement reactions

Answer 8

-a more reactive metal can displace a less reactive metal from its oxide
-a more reactive metal can displace a less reactive metal from its solution
-a more reactive metal forms a more stable carbonate that needs to absorb more heat energy to decompose by heating
-potassium and sodium are stable to heating with bunsen burner
-the rest decomposes to metal oxide and carbon dioxide gas