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Metals
& non-metals
Francine
Taylor-Campbell, Contributor
YOU
SHOULD BE ABLE TO:
- List
the general, physical and chemical
properties of metals
- Describe
the reactions of metals and their
compounds
POINTS
TO NOTE
- Metals
are generally found in groups 1,
2 and 3 of the periodic table
- A
metal describes an element that
ionizes by losing electrons and
is referred to as being electropositive
- Metals
are reducing agents
-
Most metals react with dilute acids,
water and steam. The oxides of metals
are basic (except for Al, Zn and
Pb) and react with acids to form
salt and water
- Metals
exhibit the following physical properties:
high melting and boiling points,
good electrical and thermal conductivity,
solids at room temperature (except
for Hg) and easily bent or drawn
into wires
- The
bonding in metals is responsible
for their physical properties.
As
stated earlier, metals undergo reactions
with acids, oxygen, water and steam.
The ease with which these reactions
occur is dependent on the position
of the metal in the reactivity series.
This is a list of metals arranged
in order of their reactivity or how
readily they will lose their outer
electrons. A metal that will readily
give up its electrons (eg K) is more
reactive than one that loses electrons
less readily (eg Cu). Metals at the
top of the series are the most electropositive
and the ones at the bottom are the
least electropositive.
The
reactivity series of metals
| K |
Most
reactive
|
Decreasing
reactivity, ease of ionization,
stability of compounds and strength
as reducing agents.
|
| Na |
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
V
|
| Ca |
|
| Mg |
|
| Al |
| Zn |
| Fe |
| Pb |
| (H) |
| Cu |
| Hg |
| Ag |
| Au |
Least
reactive
|
Summary
of the reactions of metals
1.
Metals react with air or oxygen to
form oxides
2Ca
+ O2 == 2CaO calcium oxide
Ag
and Au has no reaction with oxygen
2.
Metals react with water or steam to
form the oxide or hydroxide Na, K
and Ca react with cold water to form
the hydroxide and hydrogen
2Na
+ 2H2O (l) == 2NaOH + H2
Metals
above Pb react with steam to produce
the oxide and hydrogen
Mg
+ H2O (g) == MgO + H2
Below
this there is no reaction with water
or steam
3.
With dilute acids the metals higher
up in the series react violently forming
salt and hydrogen. As you go down
the list, the reaction is less vigorous
until you reach Pb, Cu, Ag and Au,
which have no reaction.
4.
The thermal stability of the nitrates,
carbonates and hydroxides of metals
is also based on the reactivity series.
The ease with which these compounds
decompose when heated increases as
you go down the series. (See text
for an outline of these reactions.)
Francine
Taylor-Campbell teaches at Jamaica
College. Send questions and comments
to kerry-ann.hepburn@gleanerjm.com
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