Assertion :BCC and HCP has same packing efficiency. Reason: Both have same number of atoms per unit cell and same arrangement.

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

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Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

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Assertion is correct but Reason is incorrect

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Both Assertion and Reason are incorrect

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Solution

The correct option is D Both Assertion and Reason are incorrect
BCC has $68$ % and HCP has $74$ % packing efficiency.
$B C C - 2$ atoms per unit cell, $H C P - 4$ atoms per unit cell
In BCC, particles are present at corners and one particle is present at the centre within the body of the unit cell. In HCP, the packing gives a hexagonal pattern.

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