What is the lowest shell which has an f-subshell?

Explanation

To determine the lowest shell that has an f-subshell, we need to understand the relationship between the principal quantum number (n) and the azimuthal quantum number (l).

### Step-by-Step Solution:

1. **Understanding Quantum Numbers**:
- The principal quantum number (n) indicates the shell level of an electron and can take positive integer values (1, 2, 3, ...).
- The azimuthal quantum number (l) determines the shape of the orbital and can take values from 0 to (n-1).

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