Question

Which of the following is not a possible sublevel?

1s
2d
3p
4f

Answer 1

The sublevels in an atom are designated by the letters s, p, d, and f, which correspond to different shapes of electron orbitals.

The possible sublevels for each principal energy level (n) are:
- For n = 1: s
- For n = 2: s and p
- For n = 3: s, p, and d
- For n = 4: s, p, d, and f

From the options you provided:
- **1s** is valid (n=1, l=0)
- **2d** is **not valid** (n=2 can only have s and p)
- **3p** is valid (n=3, l=1)
- **4f** is valid (n=4, l=3)

Thus, **2d** is the option that is not a possible sublevel.