A sample of pure silicon is doped with a trivalent impurity whose each atom creates a hole the concentration holes in pure silicon is `7xx10^(15)` holes per cubic metre and density of silicon is `5xx10^(23)` a pure silicon sample by a factor of 120 calculate approximately the proportion in which the impurity is added

Explanation

To solve the problem step by step, we will follow the given information and apply relevant formulas.

### Step 1: Understand the given data
- The concentration of holes in pure silicon, \( n_h = 7 \times 10^{15} \) holes/m³.
- The density of silicon, \( N_s = 5 \times 10^{23} \) atoms/m³.
- The factor by which the pure silicon sample is increased is 120.

### Step 2: Calculate the initial concentration of charge carriers
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