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Valency, Oxidation State and Ionic Compounds.
When a metal reacts with a non-metal,
the metal will lose electrons to form a positive ion,
the non-metal will gain electrons to
form a negative
ion.
The compound which is formed will be
ionic. It will form a giant structure.
If you do not know whether an
element is a metal
or a non-metal see the periodic table.
The valency (combining
power) of a metal is the
same
as its oxidation state (the charge on
the ion).
The number of electrons
which a metal will lose
is the same as its group number in the
periodic table.
A metal in group
1 will form a 1+
ion. (Valency 1,
oxidation state 1+).
A metal in group
2 will form a 2+
ion. (Valency 2, oxidation
state 2+).
The number of electrons
which a non-metal will gain
will be 8 minus its group number.
A non-metal in group 6 will form a 2- ion. (Valency
2, oxidation state 2-).
A non-metal in group 7 will form a 1- ion. (Valency
1, oxidation state 1-).
A non-metal ion is negative
because it has gained electrons.
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Copyright © 2008 Dr. Colin France. All Rights Reserved.