Question

Find the number of free electrons per cubic centimeter in germanium at room temperature given that there are 5.6x10-10 free electrons per atom. The density and molar mass of silicon are 5.32 g/cm3 and 72.59 g/mol, respectively.

Answer 1

Answer:

$2.41 \times 10^{13}\ free\ electrons/cm^3$

Explanation:

given,

free electron per atom = 5.6 x 10⁻¹⁰

density of silicon = 5.32 g/cm³

molar mass of silicon =  72.59 g/mol

number of moles per cubic centimeter

           = $\dfrac{5.32}{72.59}\ mole/cm^3$

number of atom per cubic centimeter

           = $\dfrac{5.32}{72.59}\times 6.022 \times 10^{23}\ /cm^3$

number of free electron per cubic centimeter

           = $\dfrac{5.32}{72.59}\times 6.022 \times 10^{23}\times 5.6 \times 10^{-10}/cm^3$

           = $2.41 \times 10^{13}\ free\ electrons/cm^3$