Calculate the radius of a platinum atom in cm, given that pt has an fcc crystal structure, a density of 21.4 g/cm3, and an atomic weight of 195.08 g/mol.

Radius of platinum atom is

Explanation:

We know, Density in solid state is also given by ,

Here, Z= total no of atom or molecule per unit cell. ( Z = 4 for FCC structure )

M = atomic weight = 195.08 gm/mol.

N_A= Avogadro's number =

a= size of side of cube.

Also for, FCC crystal    ....1

Since,

Therefore,

Putting all values ,

Putting value of a in equation 1 we get,

Hence, this is the required solution.