Platinum crystallizes with the face-centered cubic unit cell. The radius of a platinum atom is 139 pm. Calculate the edge length of the unit cell and the density of platinum in g>cm3.

Length = 393pm, Density = 21.3 g/cm^3.

Explanation:

From the question above, we have the following parameters or data which is going to aid in solving the above Question.

=> The radius of a platinum atom = 139 pm.

Therefore, the length can be calculated by making use of the formula given below:

Length = 2 √( 2r) = 2 × √ (2 × 139 × 10^-12m ) = 393 × 10^-10 m = 393pm.

The density can be calculated by making use of the chemical formula given below:

Density = mass ÷ volume = (195.064/ 6.02 × 10^23) ÷ (3.93 × 10^-10/ 10^-2) = 21.3 g/cm^3.