# NEET Chemistry The Solid State Questions Solved

BOARD

Silver metal crystallises with a face centred cubic lattice.  (5 marks)

The length of the unit cell is found to be 3.0 10–8 cm.

Calculate atomic radius and density of silver.

(Molar mass of Ag = 108 g mol–1, NA = 6.02   x 1023 mol–1).

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Concept Questions :-

Density/Formula/packing fraction/ Semiconductors

$\mathrm{r}=\frac{\mathrm{a}}{2\sqrt{2}}$                                                             (1/2 mark)

$=\frac{3.0×{10}^{-8}}{2×1.414}$                                                        (1/2 mark)

=1.06 × 10-8 cm                                                (1 mark)

$\mathrm{d}=\frac{\mathrm{zM}}{{\mathrm{a}}^{3}\mathrm{Na}}$                                            (1/2 mark)

z=4                                                    (1/2 mark)

$\mathrm{d}=\frac{4×108}{\left(3×{10}^{-8}{\right)}^{3}×\left(6.02×{10}^{23}\right)}$                     (1 mark)

=26.6 g/cm3                                                (1 mark)

Difficulty Level:

• 85%
• 16%
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