Calculate the ratio of the radius of `1^(st)` orbit of H atom to that of `4^(th)`orbit.
Hint `: r_(n) prop ( n)^(2)`

Explanation

To calculate the ratio of the radius of the 1st orbit of a hydrogen atom to that of the 4th orbit, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the relationship between radius and orbit number:**
The radius of the nth orbit (Rn) of a hydrogen atom is directly proportional to the square of the orbit number (n). This can be expressed as:
\[
R_n \propto n^2
...