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Recap
When the atoms of two or more elements react they make a
compound. A compound contains two or more elements which
are chemically combined.
When an atom has an arrangement of electrons like a noble gas
in Group 0 it is stable and unreactive. When atoms react they
take part in changes which give them a stable arrangement of
electrons.
· Sharing electrons => covalent bonding
· Transferring electrons => ionic bonding
· The group that an element is in on the Periodic Table shows
how many electrons are in its outer shell !!!…read more

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Ionic bonding
Usually occurs between metal and non-metal
In this form of bonding the metallic element will lose one or more
electrons from its outer shell which are transferred to the non-
metallic element. When the metal loses an electron there is one
more proton in the nucleus than there is the number of electrons,
meaning the overall charge is now + the number of electrons lost
e.g. Sodium (2,8,1) => (2,8) it now has a charge of +1. We call this
a positively charged ion. It now has the electronic structure of a
noble gas.
The non-metallic element gains an electron to achieve a stable
structure e.g. chlorine (2,8,7) => (2,8,8). In this case there is now
one more electron than the number of protons in the nucleus,
meaning there is now an overall charge of -1 as the charges do
not balance out. So the chlorine atom has become a negatively
charged ion.…read more

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Representing ionic bonding
Na Na
2,8,1 2,8
Cl Cl
2,8,7 2,8,8…read more

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Giant ionic structures/Lattices
The ions formed are held next to each other by very strong forces of
attraction between the oppositely charged ions. The electrostatic
forces, which act in all directions, is called ionic bonding. The ionic
bonds between the charged particles result in an arrangement of
ions that we call a giant structure (or lattice). The force exerted by
an ion on the surrounding ions in the lattice acts equally in all
directions, this is why the ions in a giant structure are held together
so strongly.
The ions that are formed when sodium and chlorine react together
are spherical in shape, so they can attract oppositely charged ions
around themselves in all directions. So many millions of ions become
bonded together.
The chloride ions are larger than those for sodium because chlorine
has 3 filled shells of electrons and sodium has only two.…read more

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It takes a lot of energy to break up a giant ionic lattice as there are lots of
strong ionic bonds to break. To separate the ions we have to overcome all
those electrostatic forces of attraction, this means that ionic compounds
have a high melting point and boiling point. Once we have supplied
enough energy to separate ions from the lattice they are free to move
around that's when the ionic compound melts and becomes molten. The
ions are free to move anywhere in this liquid, therefore ionic compounds
conduct electricity when molten (as the ions can carry the electrical
charge now they are free to move). A solid ionic compound cannot
conduct electricity as the ions are fixed in the lattice, however they can
vibrate `on the spot' when solid. _WE USE ELECTROLYSIS_
Many ionic compounds will dissolve in water, as the lattice can be split up
by the water molecules. Solutions of ionic compounds in water will ALSO
conduct electricity as ions are free to move. The ions are able to move to
an oppositely charged electrode in the solution (electrolysis).…read more

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