Given : Structure of Al
= Cubic close packed structure
= ccp structure
Edge length of unit cell = a = 353.6 pm
= 3.536 × 10-8 cm
r = ?
Number of unit cells in 1.00 cm3 of Al = ?
Radius of Al atom = r \(=\frac{a}{2\sqrt{2}} = \frac{353.6}{2\sqrt{2}}\)
\(=\frac{353.6}{2 \times 1.414}\) = 125 pm
Volume of one unit cell = a3 = (3.536 × 10-8)3
= 4.421 × 10-23 cm3
Number of unit cells \(=\frac{1.00}{4.421 \times 10^{-23}}\)
= 2.26 × 1022
Radius of Al atom = 125 pm
Number of unit cells = 2.26 × 1022
