Question

A scientist measured the cell length in a cubic crystalline substance to be 3.0×10^-8cm. The substance was also found to have a density of 11g/cc and an atomic mass of 60u. The no. Of atoms per unit cell based on data is

Answer 1

Answer:

4 is the value of z and it is the no of atoms per unit cell.

Answer 2

Answer:

According to the given data the number of atom per unit cell is 3.

Explanation:

We know that the formula of the density of a cubic crystal = (no of atom × atomic mass ) / ( volume × Avogadro's number)

Here given, density= 11 g/cc

cell length of the crystalline= 3 × 10^(-8) cm

i. e. volume = {3×10^(-8)} ^3 cc = 27× 10^(-24) cc

atomic mass = 60 u

let, the number of atom = Z

11=(Z×60) /[{27×10^(-24)} × {6×10^(-23)}]

[you have to take Avogadro's number as 6× 10^(-23) for calculation]

after doing that calculation you will find that Z= 2.97

which is approximately 3

so the answer is 3