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So far we have looked at ionic compounds as single entities.
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Ionic compounds actually exist as large three D structures, known as a giant ionic lattices.
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In this lesson, we will learn about and you got it, these giant ionic lattice structures.
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When we talk about sodium chloride, there aren't actually any individual sodium chloride molecules.
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Instead, the sodium and chloride ions are arranged in a regular repeating three D pattern, known as a giant ionic lattice.
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Let's now have a look at the giant ionic lattice of sodium chloride.
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We know that sodium and chloride ions are electrostatically attracted to one another.
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Because of this, you will see that the ions are arranged so that the sodium ions are always next to the chloride ions.
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This arrangement is seen in all directions of the three D structure.
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The electrostatic attractions in a lattice structure are very strong.
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Let's think about it!
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Each sodium ion is held in place by the electrostatic attraction of six neighboring chloride ions, in all possible three D directions,
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And similarly, each chloride ion is held in place by the electrostatic attraction of six sodium ions, also in all possible three D directions.
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Since this lattice structure is so strong, it explains some key properties of ionic compounds.
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Ionic compounds have very high melting points.
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This is because a lot of energy is required to overcome the strong electrostatic attractions holding the three D lattice structure in place.
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Ionic compounds are also very brittle.
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This means that they break rather easily into small pieces.
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A ceramic flower vase is also brittle.
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If knocked over, chances are it will break into small pieces.
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But why are ionic compounds brittle?
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When a force is applied to the three D lattice structure will disrupt the regular repeating pattern of sodium and chloride ions.
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So, the sodium ions are forced to be next to other sodium ions, and the same scene with chloride ions.
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Like charges repel one another, and this repulsion essentially breaks the latticed structure.
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In summary, ionic compounds exist as giant ionic lattices, not a single molecules.
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The giant ionic lattice is a regular repeating three D pattern of alternating positive and negative ions.
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The electrostatic attractions holding the structure intact are very strong,
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and this accounts for the fact that ionic compounds have very high melting points and are brittle.