The half-life period of radon is 3.8 days. After how many will only one-twentieth of radon sample be left over?

Explanation

To solve the problem of determining how long it will take for only one-twentieth of a radon sample to remain, given that the half-life of radon is 3.8 days, we can follow these steps:

### Step 1: Understand the half-life concept
The half-life of a radioactive substance is the time required for half of the substance to decay. In this case, the half-life of radon is given as 3.8 days.

### Step 2: Calculate the decay constant (k)
The decay constant (k) can be calculated using the formula:
\[ k = \frac{0.693}{t_{1/2}} \]
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