Properties of metals slides

Metal properties

1. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12

2. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12

3. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12
What do these pictures show
you?

5. 6.1 Properties of metals
(a)describe the general physical properties of metals as solids
having high melting and boiling points, being malleable, ductile and
good conductors of heat and electricity
(b) describe alloysas a mixture of a metal with another element, e.g.
brass; stainless steel
(c) identify representationsof metals and alloys from diagrams of
structures
6.2 Reactivity series
(a) place in order of reactivity calcium, copper, (hydrogen), iron, lead,
magnesium, potassium, silver, sodium and zinc, by reference to the
reactions, if any, of the metals with water, steam and dilute
hydrochloric acid
(b) deduce the order of reactivity from a given set of experimental
results

6. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12

7. The Importance of Metals
•Metals are useful because of their properties.
•Metals have both physical and chemical properties.

8. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12

9. Physical Properties of Metals
•Metals have high melting and boiling point.
A large amount of heat energy is required to overcome
the strong forces of attraction between positively
charged ions and delocalised electrons.
There are exceptions to the above properties of metals.
E.g. Mercury and Group Imetals have low melting and
boiling point
•Metals are malleable ( bent to form shapes) and ductile
(stretched to form wires)
Since there is a regular arrangement of ions in layers,
the layers of ions can slide over each other easily when
a force is applied without breaking the metallic bonds.

10. Physical Properties of Metals
The layers of atoms can slide over one another

11. Physical Properties of Metals
•Good conductors of heat and electricity
Presence of mobile electrons allows electrical
charges to be transferred throughout the metal.
When one end of a piece of metal is heated, the
positive ions vibrate more vigourously. The vibrating
ions transfer energy to the mobile electrons. These
mobile electrons move to other parts of the metal
and transmit energy to other positive ions.

12. Physical Properties of Metals
•High Density
Atoms are usually packed together as closely as
possible.
Most metals have a high density because there is little
empty space between the closely packed atoms.
The 3-D arrangement of
atoms in a typical metal Simplified diagram of a metal
structure. The atoms are
packed together very closely.

13. Physical Properties of Metals
Alloys
•An alloy is a mixture ofa metal with one or
few of other elements (metals or non -
metals)
•Alloys are much stronger and harder than
pure metals.

14. So, why are alloys stronger and
harder than pure metals?

15. •Different metals have different size atoms.
•The different sizes of atoms disruptsthe
orderly layers of atoms and makes it more
difficultfor the layers to slide overeach other.
Physical Properties of Metals
•Thus, alloys are harder and stronger than pure
metals.
Simplified structure of an alloy
Alloys

16. •Some examples of alloys:
–Steel: Iron, carbon
–Stainless steel: Iron, carbon, nickel and
chromium
–Brass: Copper, Zinc
The pins of these cable plugs are made of
brass
All these coins consist of
copper alloy

17. Brass
Simple structure of brass
Copper
Zinc

18. •Metals have the following properties:
–High densities.
–High melting points.
–Are malleable and ductile.
–Conduct electricity & heat.

19. Question Time!
•List 4 physical properties of metals
•What is an alloy?
•Which structure belongs to pure metal?
•Which structure belongs to alloy?
A
B

20. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12
•Try Eg 1 -2

22. The Reactivity Series
•The reactivity
series is the
order in which
metals are listed
accordingto
their chemical
reactivity.
•The most
reactive metal is
at the top.

23. Mercury
Silver
Gold
P
S
C
Potassium
Sodium
Calcium
M
A
Z
I
L
H
C
M
S
G
MEMORISE!!!!

24. Reactivity Series
Potassium Please
Sodium Send
Calcium Cats
Magnesium Monkeys
Aluminium And
Zinc Zebras
Iron In
Lead Large
(Hydrogen) Hired
Copper Cage,
Mercury Make
Silver Sure
Gold Good!
Please
Stop
Calling
Mark
A
Zukerberg
In
London
He’s
Called
Mr
Social
Guy

25. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12
Each pictures shows properties
of metals.
What are they ?

26. The Reactivity Series
•Metal ‘high up’ in the reactivity series:
react vigourously
Readily lose electrons to form + ions
Corrodes easily
•Metal ‘low down’ in the reactivity series:
Does not react vigourously
Does not readily lose electrons to form + ions
Does not corrodes easily

27. The Reactivity Series
•The position of aluminium:
Appears to be unreactive although “high” in the
reactivity series
-Metal is covered with a thin layer of aluminium oxide
that protectsthe metal from reacting.
•Hydrogen in the Reactivity Series:
-Metals below hydrogen in the series do not react
with acids to produce hydrogen gas.
•Examples: Copper, Mercury, Silver, Gold

28. •The reactivity series compares the
reactivity of metals. Metals ‘high up’ in
the series are very reactive. Metals ‘low
down’ in the series are not very reactive.
•Metals below hydrogen do not react
with acids.

29. Chemical Properties of Metals
•Chemical properties describe how substances
react, i.e. how they change into other
substances.
•Metals that react vigorously are said to be
reactive metals.
•Metals that do not react are unreactive metals.
How do you know if a
reaction is vigorous or not?

30. Chemical Properties of Metals :
Reaction of Metals with Water
•Some metals react vigorously with cold water or
steam; others do not react at all.
•When a metal does react with water, the
products formed are: metal hydroxide&
hydrogen
Potassium is a very reactive
metal, it reacts violently with
water to form :
Potassium hydroxide (an alkali)
and Hydrogen gas
Eqn. : K (s) + H
2O (l) → KOH (aq) + H
2 (g)2 2 2

31. Reaction of Metals with Water
Word eqn:Calcium + Water → Calcium
hydroxide + Hydrogen gas
Balanced chemical equation :
Ca (s) + 2 H
2O (l) → Ca(OH)
2(aq) + H
2(g)
Calcium reacts readily with cold water to form:
……………………………………………………………………………..
Calcium hydroxide & hydrogen gas

32. Reaction of Metals with Water
•When a metal does react with steam, the products formed
are: metal oxide and hydrogen gas.
Magnesium + steam →
Magnesium oxide+ Hydrogen gas
Balanced chemical equation :
Mg (s) + H
2O (g) → MgO (s) + H
2 (g)
Try writing the eqn!
Hint: Mg is in Grp II

33. Chemical Properties of Metals
Reaction with Dilute Hydrochloric Acid
•Many metals react with dilute hydrochloric acid.
•The products are a metal chloride and hydrogen gas.
Test for hydrogen gas:
Place a burning / lighted splint
at the mouth of the test tube.
Result –The lighted splint is
extinguished with a ‘pop’sound.

34. Reactions of Metals with Acid
•Check out the video:
–YouTube video on potassium’s reaction with
HCl:
http://www.youtube.com/watch?v=31YLkZJCe
a4&feature=related

35. Reaction with Dilute Hydrochloric Acid
copper
zinc magnesium

36. Equations :
•Cu (s) + HCl (aq) → No reaction
Try writing the eqn!
•Zn (s) + 2 HCl (aq) →ZnCl
2(aq) + H
2(g)
Hint
Zn ion formula: Zn
2+
Chlorine, Cl, is in group VII.
•Mg (s) + 2 HCl (aq) → MgCl
2(aq) + H
2(g)

37. Chemical Properties of Metals
Metal
Reaction with
Cold Water
Reaction with
Steam
Observations
Potass
ium
Explosion
Extremely
explosive
A lot of heat is produced which
causes the hydrogen to catch
fire and explode.
Equation:
2K + 2H
2O 2KOH + H
2
Sodiu
m
Vigourous Explosive
A lot of heat is produced which
causes the hydrogen to catch
fire and explode.
Equation:
2Na + 2H
2O 2NaOH + H
2
Calciu
m
Moderate Explsoive
Equation:
Ca + 2H
2O Ca(OH)
2+ H
2

38. Metal
Reaction with
Cold Water
Reaction with
Steam Observations
Magnes
ium
Very slow
Vigourous
Equation: Mg (s) + 2H2O (l) →
Mg(OH)2(aq) + H2(g)
hot magnesium burns in steam
with bright light
Equation: Mg+ H
2O MgO + H
2
Zinc
No reaction
Moderate
Hot zinc burns in steam
equation:Zn + H
2O ZnO + H
2
Iron No reaction Slow
red hot iron reacts slowly with
steam
equation:
3Fe + 4H
2O Fe
3O
4(s) + 4H
2
Lead No reaction No reaction
Copper No reaction No reaction
SilverNo reaction No reaction

39. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12Chemical Properties of Metals
Metal
Reaction
with Dilute
Hydrochlori
c Acid
Observations
Potassium
Explosive
Equation:
2K (s) + 2HCl (aq) → 2KCl (aq) + H
2(g)
Sodium
Explosive
Equation:
2Na (s) + 2HCl (aq) → 2NaCl (aq) + H
2(g)
Calcium
Very fast
Equation:
Ca (s) + 2HCl (aq) → CaCl
2(aq) + H
2(g)

40. Metal
Reaction with Dilute
Hydrochloric Acid
Observations
Magnesium
Fast
Mg (s) + 2HCl (aq) → MgCl
2(aq) + H
2(g)
Zinc
Moderately fast
Zn (s) + 2HCl (aq) → ZnCl
2(aq) + H
2(g)
Iron
Slowly
pale green solution of iron (II) chloride is
produced.
Fe (s) + 2HCl (aq) → FeCl
2(aq) + H
2(g)
Lead
V. slowly
Copper
No rxn
Silver
No rxn

41. •Most metals react with water. The reactive metals
can react with cold water.
metal + water metal hydroxide + hydrogen
The less reactive metals react when heated in
steam.
metal + steam metal oxide + hydrogen
•Most metals react with dilute hydrochloric acid.
metal + hydrochloric acid metal chloride +
hydrogen

42. Properties of Metals
T H E M E F O U R :P E R I O D I C I T Y
C h a p t e r12
Try Eg 3 -5

43. Exercise :
1 Y is a metal. From this information alone, it may be deduced that
Y
A is very reactive
B is denser than water
C cannot exist as a gas
D reacts by giving away electron(s).
2 Which one of the following best represents the structure of an
alloy?
A B
C D
( C )
( D )

44. 3 Aluminium is found to be very resistant to corrosion.
Which one of the following statements correctly explain
this observation?
A Aluminium is an unreactive metal
B Aluminium does not react with acid or oxygen
C The oxide layer that is formed on the surface of
aluminium protect it.
D Aluminium is stronger and harder than most
metals.
( C )

45. 5 The relative positions of metals X, Y and Z in the activity series are
indicated by the following abbreviated table.
Metal X
Calcium
Magnesium
Metal Y
Iron
Hydrogen
Copper
Metal Z
In each case, select from the metals X, Y and Z the one
which
(i)Does not react with dilute HCl:
(ii)Reacts readily with cold water :
(iii) Does not react with cold water
but reacts with dilute hydrochloric acid :
(iv)Will displace magnesium from
magnesium sulfate solution :
(v) Will have no reaction with
copper (II) sulfate solution :
Z
X
Y
X
Z

46. 6The properties of 5 metals are listed as follows :
Metal Reaction with water Reaction with dilute acids
A Does not react with steam Does not react with acids
B Sink in cold water and reacts Reacts violently with
to produce hydrogen gas dilute acids
C Reacts slowly with steam Slow effervescence with
dilute acids
D Reacts with steam to formSteady effervescence with
a yellow residue which dilute acids
becomes white when cooled
E Dissolves violently in waterToo violent to react with
and floats on the surfacedilute acids
as a silvery ball

47. a)Choose the letter that represents
(i) the least reactive metal :
(ii) the most reactive metal :
b)Choose a letter for the metal that could be
(i) Sodium : (ii) Calcium :
(iii) Copper : (iv) Iron :
(v) Zinc :
A
E
A
D
E
C
B

48. 7) Metals and non-metals have different physical and
chemical properties.
State any two differences between metals and non-metals,
illustrating your answer using the properties of carbon and
iron.
Iron Carbon
•High melting and
boiling point
•Low melting and
boiling point
•High density •Low density
•Good conductor of
heat
•Poor conductor of
heat
•Ductile •Not ductile
•Malleable •Brittle and break
easily

49. 8) Give three physical properties of metals and suggest
three uses related to these properties.
•Good conductor of electricity
•Uses: Used to make electrical wires
•Ductile and malleable
•Uses: Used to make electrical wires
•High melting point
•Uses: Used to make the filament of light
bulbs