TG EAMCET 4 May 2025 Shift 1 Paper

Sodium crystallises in a body centred cubic (bcc) lattice with an atomic radius of 1.86

∘

A

. Let, the edge length of the unit cell be x

∘

A

.
In a bcc lattice, the body diagonal is equal to 4r, where r is the atomic radius. The body diagonal is also equal to √3x.
So,
√3x‌=4×1.86
√3x‌=7.44
x‌=‌

7.44

√3

=‌

7.44

1.732

≈4.29

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A

.
Therefore, the edge length x is 4.29

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A

.