The length of the edge of its unit cell is mathematically given as
a = 420 pm
Extending from one point to another, length is the unit of measurement for distance.
According to the SI, length is a distance dimension. Typically, a length unit is selected as the basis for the system, with all other units of measurement being derived from it.
The metre is the fundamental length standard used throughout the International System of Units.
Generally, the equation for density is mathematically given as
density = Z x M / No x a3
Therefore
density = 4 x 74.6 / 6.02x10^23
density = 6.67 g/cm3
In conclusion,
6.67 g/cm3 = (4)(74.6) / (6.02x1023)(a3)
a3 = 7.43x10-23 cm3
a = 420 pm
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