# NEET Chemistry The Solid State Questions Solved

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The density of copper is 8.95 g cm-3. It has a face centred cubic structure. What is the radius of copper atom? (Atomic mass Cu = 63.5 g mol-1, NA = 6.02 $×$1023 mol-1)

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Concept Questions :-

Density/Formula/packing fraction/ Semiconductors

Using $\rho$ = $\frac{Z×M}{{a}^{3}×{N}_{A}}$

[Given : $\rho$ = 8.95 g cm-3, For FCC; Z=4]

a3$\frac{Z×M}{\rho ×{N}_{A}}$

or  a3$\frac{4×63.5}{8.95×6.02×{10}^{23}}$ = $\frac{254}{53.879×{10}^{23}}$

or a = $\sqrt[3]{4.714×{10}^{-23}}$ = $\sqrt[3]{47.14×{10}^{-24}}$

= 3.613$×$10-8 cm

Difficulty Level:

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