Which of the following statements is correct | vedclass

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(C) In an $fcc$ unit cell,the number of atoms $(Z)$ is $4$. The number of octahedral voids is equal to $Z = 4$,and the number of tetrahedral voids is

Vedclass · Accepted Answer

Octahedral voids are present at the body center and edge centers.

Vedclass · Answer

(C) In an $fcc$ unit cell,the number of atoms $(Z)$ is $4$. The number of octahedral voids is equal to $Z = 4$,and the number of tetrahedral voids is equal to $2Z = 8$. Thus,statement $(a)$ is incorrect. Tetrahedral voids are located on the body diagonals,not at the edge centers. Thus,statement $(b)$ is incorrect. In an $fcc$ lattice,octahedral voids are located at the body center $(1)$ and at the centers of each of the $12$ edges $(12 	imes 1/4 = 3)$,totaling $4$. Thus,statement $(c)$ is correct. The packing efficiency of both $fcc$ and $hcp$ lattices is $74 \%$. Thus,statement $(d)$ is incorrect.

Which of the following statements is correct for an $fcc$ lattice?

Similar Questions

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Fill in the blanks:
$(a)$ In $ccp$ structure,$a = \dots \dots r$.
$(b)$ In $hcp$ structure,packing efficiency $= \dots \dots \%$.
$(c)$ In $bcc$ structure,percentage of packing efficiency $= \dots \dots \%$.

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