Calculate the total number of disintegration for a radioactive isotope in the twentieth hour which is measured from a time when activity was 2 Ci. Given that the half-life of the isotope is 20 h.

Explanation

To solve the problem of calculating the total number of disintegrations for a radioactive isotope in the twentieth hour, we can follow these steps:

### Step 1: Understand the Given Information
- Initial activity \( A_0 = 2 \, \text{Ci} \)
- Half-life \( t_{1/2} = 20 \, \text{h} \)
- We need to find the total number of disintegrations in the 20th hour.

### Step 2: Convert Activity from Curie to Disintegrations per Second
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