In diamond, carbon atom occupy FCC lattice points as well as alternate tetrahedral voids. If edge length of the unit cell is 356 pm, then radius of carbon atom is :-
$$\sqrt{3}a = 4(2r)$$
Here , $$a = 356 \ pm $$
$$\therefore r = \frac{\sqrt{3} \times 356}{8} = 77.07 \ pm$$
The density of lead is 11.35 g $${\text{c}}{{\text{m}}^{{\text{ - 3}}\,\,\,\,}}\,\,$$ and the metal crystallizes with fce unit cell. Estimate the radius of lead atom. ( At, Mass of lead = 207 g $${\text{mo}}{{\text{l}}^{\text{ - }}}^1$$ and $$\,{{\text{N}}_{\text{A}}}{\text{ = 60}}{\text{.2}}\, \times {\text{1}}{{\text{0}}^{{\text{23}}}}\,{\text{mo}}{{\text{l}}^{\text{ - }}}^1$$
Answer the following questions . What is the radius of sodium atom if it crystallises in bcc structure with the cell edge of $$ 400 \, pm $$ ?
Chromium crystallises in bcc structure . If its atomic diameter is $$ 245 \,pm $$ , find its density . Atomic mass of $$ Cr = 52 \, amu $$ and $$ N_A = 6.02 \times 10^{23} \, mol^{-1} $$ .
The edge length of unit cell of a metal having molecular weight $$75$$ g/mol is $$5\ \mathring A$$ which crystallizes in cubic lattice. If the density is $$2\ g/cc$$, then find the radius (in pm) of metal atom $$(N_{A}=6\times 10^{23})$$. Give answer in $$pm$$.
Tungsten has a body-centred cubic lattice and each lattice point is occupied by one atom. Calculate the radius of metallic tungsten if density of tungsten is $$19.30 g cm^{-3}$$ and at, wt is 183.9.
Gold has a close- packed structure which can be viewed as spheres occupying 0.74 of the total volumed. If the density of gold is 19.3 g/cc, calculate the apparent radius of a gold ion in the solid.
The density of solid argon is 1.65 g/mL at $$-233^{\circ}$$C. If the argon atom is assumed to be sphere of radius $$1.54 \times 10^{-8}$$ cm. What percentage of solid argon is apparently empty space? (At.wt of Ar=40)
At room temperature, sodium crystallizes in body centred cubic lattice with a=4.24 $$A^{\circ}$$. Calculate theoretical density of sodium (At. wt. of Na=23)
Niobium crystallizes in body centred cubic structure. If density is $$8.55 g cm^{-3}$$, calculate atomic radius of niobium using its atomic mass 92.90.
Aluminium crystallizes in a cubic close-packed structure. Its metallic radius is 125 pm. (a) What is the length of the side of the unit cell? (b) How many unit cell are there in 1.00 $$cm^3$$ of aluminium?