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Question
How are tetrahedral and octahedral voids formed?
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Solution
- Two dimensional hexagonal close-packed layer has triangular voids which is formed by three spheres.
- When the triangular voids of the first layer are covered by spheres of the next layer, tetrahedral voids are formed. A tetrahedral void is surrounded by four spheres.
- The overlapping triangular voids from the two layers together form an octahedral void.
An octahedral void is surrounded by six spheres. - Thus, the depressions in which spheres of second layer rest are tetrahedral voids while the depressions in which no sphere rests are octahedral voids.
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