TOPIC: TRANSITION
METALS/ ELEMENTS
• Between groups 2 and 3
• They are:
•
•
•
•
https://www.youtube.com/watch?v=m0Uj7mSC6HU
Harder
Denser
Stronger
Have higher melting
points
than group 1 metals
• They are good conductors
of heat and electricity
• They are less reactive than
group 1 metals
• Mercury (Hg) is an
exception. It has a low
melting point. It’s the only
metal that is a liquid at
room temperature.
Extension: Draw a mind map for the properties
of transition elements.
How does this data show that sodium is a typical group 1 metal and
chromium is a typical transition metal?
What do we know about
the density of transition
metals compared to
group 1 metals?
What do we know about
the melting point of
transition metals
compared to group 1
metals?
Do Na and Cr follow
these patterns? How can
you demonstrate that,
using the data?
Group 1 metals react readily with oxygen, at room
temperature, whereas transition metals react with
oxygen either very slowly, or only with heat.
Transition metals do not
react with water, unlike the
alkali metals – which react
vigorously with water!
Transition metals can also
react with halogens, to form
metal halides.
3
1
2
4
What product would be formed in each of these reactions?
1.
2.
3.
4.
5.
Iron + Chlorine
Sodium + Bromine
Manganese + Iodine
Chromium + Chlorine
Lithium + Fluorine
HINT:
When they react, halogens
change their endings from –ine to
–ide
Challenge:
Which of these reactions will be the most vigorous? Which pair or pairs are the most
reactive?
Transition metals form positive ions like all metals
However, each transition metal can form positive ions with
different charges.
• E.g. copper can form Cu+ and Cu2+.
• E.g. chromium can form Cr2+ and Cr3+.
• E.g. iron can form Fe2+ and Fe3+
In transition metal compounds we use roman numerals to
show the charge
E.g. iron (III) oxide tells you the iron is a 3+ ion
copper (II) oxide tells you the copper is a 2+ ion
Write a balanced symbol equations for each of these reactions
Copper + oxygen → copper (II) oxide
Iron + oxygen  Iron (III) oxide
HINT:
The number in brackets tells you
the charge on the metal ion. So,
Nickel (II) oxide shows that the Ni
ion has a +2 charge.
Remember that the oxide ion has
a -2 charge. The overall compound
should be neutral – the charges
should balance.
Chromium + oxygen  Chromium (III) oxide
Manganese + oxygen  Manganese(II) oxide
Challenge:
Try writing the symbol equation for the reactions of the +2 and +3 ions for each metal
How does that affect the compound and the balancing of the equations?
Transition metals form coloured compounds. You will
probably have seen (or made) copper sulphate crystals –
which are bright blue.
Not only do different
transition elements
make different coloured
compounds, but the
same elements can
make different coloured
compounds depending
on the charge of their
ion.
Carry out some research to find the names of the
transition metal compounds that are the catalysts in
the following reactions:
1. Haber process (making ammonia)
2. Contact process (making sulphuric acid)
3. Decomposition of Hydrogen Peroxide
Extension Question:
In 1973 aluminum wire was found to be dangerous by the U.S.
Consumer Product Safety Commission and is not advised for
electrical wiring any longer. Why were Al wires replaced with Cu ?
Aluminum is susceptible to oxidation. This occurs when it comes into contact with moisture and
dissimilar metals. The oxidization increases resistance in this connection. With too much built up
resistance the wire can heat up possibly melt surrounding insulation which could trigger a fire.
For further Refrence :
https://www.bryantelectricservice.com/aluminum-vs-copper-wiring/
1A
B
C
1B
1C