How many atoms would be needed to show all the possible transitions from n = 4 to n = 1 in the hydrogen atom?

Explanation

To determine how many hydrogen atoms are needed to show all possible transitions from the energy level n = 4 to n = 1, we can analyze the transitions that can occur between these energy levels.

### Step-by-Step Solution:

1. **Identify the Energy Levels**:
The hydrogen atom has discrete energy levels denoted by quantum numbers n = 1, 2, 3, and 4. We are interested in transitions starting from n = 4 down to n = 1.

2. **List Possible Transitions**:
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