Structure of simple ionic crystals

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Structure of simple ionic crystals:

 In ionic crystals lattice positions are occupied by positive and nagatives ions in equivalent amounts. In such crystals positive ions are surrounded by negative ions and vice-versa. Since the coulombic forces holding the oppositely charged ions together in an ionic crystal are non directional, the arrangement of ions in the crystal is largely controlled by the sizes and charges of the ions concerned. Normally, each ion is surrounded by the largest number of oppositely charged ions. The number of oppositely charged ions surrounding an ion is the co ordination number of the ion and is related to the relative sizes of the positive and nagative ions. We will discuss below the different types of ionic compounds, depending upon the relative number of positive and nagative ions present in them.

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