REFERENCE SECTION: ABUNDANCES
Most elements occur in the Earth's crust in a chemically combined state
as minerals; a mineral is a naturally occurring pure compound, whereas
an ore contains one or more minerals mixed with other substances [such
as sand, which is mainly silicon(IV) oxide]. The two commonest elements
in the Earth's crust are the non-metals oxygen and silicon (46.4% and 
28.2%, respectively); eight of the next ten commonest are metals (see,
The Handbook of Physics and Chemistry, CRC Press, Boston, 1990). *  #

First, complete the Table below, which lists the abundances of the
eight commonest metals in the Earth's crust, by inserting the correct 
name of the metal (note the formula and Mr of the stated compound).

         Metal (M)

  Most abundant compound of metal M  

  Name 

  Abundance / %  

        Formula 

    Mr

  Aluminium  

       8.3

          M2O3

   102

       5.6

          M2O3

   160

       4.2

          MCO3

   100

       2.4

          MCl

    58.5

       2.3

          MCO3

    84

       2.1

          MCl

    74.5

       0.6

          MO2

    80

       0.1

          MO2

    87

                                                                    [7]
And second, noting that the qualitative independent variable is shown 
as separate blocks on the horizontal axis, and that the quantitative 
dependent variable is a linear scale on the vertical axis, complete the 
bar-graph of the data above.
         _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
A       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
b   8.0_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
u       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
n       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
d       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
a       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
n   6.0_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
c       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
e       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
        |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
o       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
f   4.0_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
        |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
m       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
e       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
t       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
a   2.0_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
l       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
        |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
/       |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
        |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
%   0.0_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
        |  Al | |     | |     | |     | |     | |     | |     | |     |
   
                                   Metal (M)
                                                                    [7]
*  The Earth's crust is regarded as the layer measured from the surface
to a depth of about 40 km.
#  Hydrogen and carbon, the elements which form more compounds than all
the others together, are the 10th and 17th most abundant, respectively.

REFERENCE SECTION: ALLOYS
An alloy can be defined as 'a solid solution composed of two or more 
metals, or of a metal or metals with one or more non-metals'. Although
alloys may be used either to replace or to conserve more expensive
metals, most are used to change the metals' physical properties, (i.e.,
conductivity, density, ductility, hardness, lustre, malleability,
melting point, and tensile strength), and/or chemical properties (e.g.,
resistance to corrosion). *

Complete the Table below, which includes some of the most important 
alloys, by inserting the correct name of the alloy from this list: 
Brass; Bronze; Cupro-nickel; Dental amalgam; Duralumin; Manganin;
Nichrome; Pewter; Solder; Stainless steel; and Steel.

    Alloy    

 Typical composition 

       Special properties

 Fe(99%),  C(1%)

 Stronger than iron, and more
 corrosion resistant

 Al(95%),  Cu(4%),
 Mn(0.5%), Mg(0.5%)

 Density as low as aluminium,
 but much stronger and more
 corrosion resistant

 Cu(85%),  Sn(15%)

 Stronger than copper, but just
 as corrosion resistant

 Fe(85%),  Cr(14%),
 Ni(1%)

 Harder than steel, and much
 more corrosion resistant

 Sn(85%),  Cu(7%),
 Bi(6%),   Sb(2%)

 Stronger than tin, but still
 easy to etch and engrave

 Cu(81%),  Mn(15%),
 Ni(4%)

 Suitable for fixed resistors
 because of high resistivity and
 low temperature coefficient

 Cr(80%),  Ni(20%)

 Suitable for resistance heating
 because of high resistivity and 
 high melting point

 Cu(75%),  Ni(25%)

 Attractive appearance for coins
 (looks like silver)

 Pb(67%),  Sn(33%)

 Harder than lead, but has a
 much lower melting point

 Cu(60%),  Zn(40%)

 More easily shaped by stamping
 and machining than bronze

 Sn(44%),  Hg(33%),
 Ag(22%)

 Resistant to corrosion from
 the acidic products excreted
 by mouth bacteria

                                                                   [11]
*  An alloy should not be defined as 'a mixture of metals ...'. Whilst
an alloy is indeed a mixture, the term 'mixture' implies that there is
no chemical bonding between the components: whereas, usually, there is 
between these in solutions. To place this ostensibly subtle difference 
in true perspective, compare or reflect upon the physical and chemical 
properties of the contents of two test-tubes: one containing a mixture 
of powdered tin and lead, and the other solder.

Dr. R. Peters                   Next                     Contents' List