The correct relationship between unit cell ed | vedclass

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(C) For Face-Centred Cubic $(FCC)$ structure:In $FCC$,the atoms touch along the face diagonal.The face diagonal is $a \sqrt{2} = 4 r$.Therefore,$a = 2

Vedclass · Accepted Answer

$2 \sqrt{2} r = a$ and $4 r = \sqrt{3} a$

Vedclass · Answer

(C) For Face-Centred Cubic $(FCC)$ structure:In $FCC$,the atoms touch along the face diagonal.The face diagonal is $a \sqrt{2} = 4 r$.Therefore,$a = 2 \sqrt{2} r$ or $r = \frac{a}{2 \sqrt{2}}$.For Body-Centred Cubic $(BCC)$ structure:In $BCC$,the atoms touch along the body diagonal.The body diagonal is $a \sqrt{3} = 4 r$.Therefore,$r = \frac{\sqrt{3} a}{4}$ or $4 r = \sqrt{3} a$.Comparing these with the given options,the correct relationships are $2 \sqrt{2} r = a$ and $4 r = \sqrt{3} a$.

The correct relationship between unit cell edge length '$a$' and radius of sphere '$r$' for face-centred and body-centred cubic structures respectively are:

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