Using `s, p, d` notations, describe the orbital with the following quantum numbers.
a. `n=1, l=0,` b. `n=3, l=1`
c. `n=4, l=2,` d. `n=4, l=3`

Explanation

To describe the orbitals using `s, p, d` notations based on the given quantum numbers, we will follow a systematic approach.

### Step-by-Step Solution:

1. **Understanding Quantum Numbers:**
- The principal quantum number `n` indicates the main energy level or shell.
- The azimuthal quantum number `l` indicates the subshell and can take values from `0` to `n-1`. Each value of `l` corresponds to a specific type of subshell:
- `l = 0` corresponds to the `s` subshell
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