Question

How many unit cells are present in 1.00 cm³ of of aluminum crystal, if edge length of unit cell is 3.54 × 10^-8 cm?

Options

• 4.508 × 10²² 

• 6.022 × 10²³

• 1.126 × 10²² 

• 2.254 × 10²² 

Answer 1

2.254 × 10²² 

Explanation:

a = 3.54 × 10^-8 cm

a³ = (3.54 × 10^-8)³ = 4.436 × 10^-23 cm³

No. of unit cells = `"Vol. of Aluminium"/"Vol. of. unit cell"`

`= (1 "cm"^3)/(4.436 xx 10^-23 "cm"^3)`

= 2.254 × 10²²