Answer:-

Given: Type of unit cell is ccp.
Edge length (a) = 353.6 pm = 3.536 × 10^–8 cm Volume (V) of Al = 1.00 cm³

To find:

1. Radius of Al atom (r)

2. Number of unit cells in 1.00 cm³ of Al

Formulae:

1. For ccp (fcc) unit cell, r = 0.3535 a

2. Number of unit cells in volume (V) of metal = V/a³

Calculation:

1. Using formula (i),

r = 0.3535 a

∴ r = 0.3535 × 353.6 = 125 pm

2. Using formula (ii),

Number of unit cells in volume (V) of metal = V/a³

∴ Number of unit cells in 1.00 cm³ of Al = `(1.00)/(3.536 xx 10<sup>-8</sup>)<sup>3</sup> = 2.26 x 10<sup>22</sup>`

1. Radius of Al atom (r) is 125 pm.

2. Number of unit cells in 1.00 cm3 of Al is 2.26 × 10²².