Calcium has a cubic closest packed structure (fcc) as a solid. Assuming that calcium has an atomic radius of 197 pm, calculate the density of solid calcium. (1 pm = 10-12 m, 100 cm = 1 m)

Respuesta :

Answer:

[tex]1.536 g/cm^3[/tex] is the density of solid calcium.

Explanation:

Formula used :  

[tex]\rho=\frac{Z\times M}{N_{A}\times a^{3}}[/tex]

where,

[tex]\rho[/tex] = density

Z = number of atom in unit cell

M = atomic mass

[tex](N_{A})[/tex] = Avogadro's number  

a = edge length of unit cell

We have:

r = 197 pm = [tex]197\times 10^{-12} m = 197\times 10^{-12}\times 100 cm[/tex]

[tex]r=197\times 10^{-10} m[/tex]

[tex]a=r\times 2\sqrt{2}[/tex]

[tex]a=197\times 10^{-10} m\times 2\sqrt{2}=557.200\times 10^{-10} cm[/tex]

M = 40 g/mol

Z = 4

On substituting all the given values , we will get the value of 'a'.

[tex]\rho =\frac{4\times 40 g/mol}{6.022\times 10^{23} mol^{-1}\times (557.200\times 10^{-10} cm)^{3}}[/tex]

[tex]\rho =1.536 g/cm^3[/tex]

[tex]1.536 g/cm^3[/tex] is the density of solid calcium.