Question

How many free electrons are there in 2.55 cm^ ^ 3 of pure Silicon Note N = Vp and rho = 1.54 free electrons / cm ^3

A: 3.93 x 10^20 free electrons
B: 6.32 x 10^20 free electrons
C: 3.93 x 10^22 free electrons
D: 6.32 x 10^2× free electrons

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Answer 1

C: 3.93 x 10^22 free electrons

Step-by-step explanation:

The no. of free electrons can be found out using the following formula:

`N = V\rho\\`

where,

N = No. of free electrons = ?

V = Volume = 2.55 cm³

ρ = density of electrons = 1.54 x 10²² free electrons/cm³

Therefore, using these values in the equation, we get:

`N = (2.55\ cm^3)(1.54\ x\ 10^(22)\ free\ electrons/cm^3)\\`

N = 3.93 x 10²² free electrons

Therefore, the correct option is:

C: 3.93 x 10^22 free electrons