part 2 of 2
which violate hunds rule? check all that apply.
none of the above

Question

Accepted Answer

To determine which electron configurations violate Hund's rule, we recall Hund's rule: electrons in degenerate orbitals (same energy) fill them singly with parallel spins before pairing up.

### Analyzing each option:
1. **First configuration ( $ \boldsymbol{\uparrow\quad\uparrow\downarrow\quad\uparrow\quad\uparrow\downarrow\quad\uparrow\downarrow} $)**:
   Degenerate orbitals (each box is a degenerate orbital). Electrons first fill singly (parallel spins) then pair. Here, some orbitals have single electrons (parallel $ \uparrow $) and others have pairs. This follows Hund’s rule (no violation).

2. **Second configuration ( $ \boldsymbol{\uparrow\quad\uparrow\quad\uparrow\downarrow} $)**:
   Three degenerate orbitals. The first two have single $ \uparrow $ electrons (parallel), but the third orbital has a pair ($ \uparrow\downarrow $) before all orbitals have single electrons. This violates Hund’s rule (electrons paired in an orbital before all orbitals have one electron).

3. **Third configuration ( $ \boldsymbol{\uparrow\quad\uparrow\quad\downarrow\quad\uparrow\quad\uparrow} $)**:
   One orbital has a $ \downarrow $ electron while others have $ \uparrow $. Electrons in degenerate orbitals should have parallel spins when singly occupied. The $ \downarrow $ spin (opposite to $ \uparrow $) in a singly - occupied orbital violates Hund’s rule (spin - pairing before all orbitals are singly filled, and incorrect spin alignment for single electrons).

4. **Fourth configuration ( $ \boldsymbol{\uparrow\downarrow\quad\uparrow\downarrow\quad\downarrow\downarrow\quad\uparrow\downarrow\quad\uparrow} $)**:
   Orbitals have paired electrons or a single $ \uparrow $, but one orbital has $ \downarrow\downarrow $ (invalid, as electrons in an orbital must have opposite spins, but also, the $ \downarrow\downarrow $ is a violation of Pauli exclusion principle, and also, the filling order violates Hund’s rule (pairing and incorrect spin alignment in singly - occupied - like orbitals). However, more directly, the third and second configurations clearly violate Hund’s rule, and the fourth also has issues, but let's focus on the key violations.

### Correct Violations:
- The second configuration ( $ \uparrow\quad\uparrow\quad\uparrow\downarrow $): Pairs electrons in an orbital before all degenerate orbitals have one electron.
- The third configuration ( $ \uparrow\quad\uparrow\quad\downarrow\quad\uparrow\quad\uparrow $): Incorrect spin ( $ \downarrow $) in a singly - occupied orbital (should be parallel $ \uparrow $ before pairing).
- The fourth configuration ( $ \uparrow\downarrow\quad\uparrow\downarrow\quad\downarrow\downarrow\quad\uparrow\downarrow\quad\uparrow $): Has $ \downarrow\downarrow $ (Pauli violation, and also Hund’s rule violation due to incorrect filling).

But from the given checkboxes (assuming the third was pre - checked, but let's re - evaluate):

- The second row ( $ \uparrow\quad\uparrow\quad\uparrow\downarrow $): Violates Hund’s rule (pairs too early).
- The third row ( $ \uparrow\quad\uparrow\quad\downarrow\quad\uparrow\quad\uparrow $): Violates Hund’s rule (incorrect spin in single orbital).
- The fourth row ( $ \uparrow\downarrow\quad\uparrow\downarrow\quad\downarrow\downarrow\quad\uparrow\downarrow\quad\uparrow $): Violates Hund’s rule (and Pauli, but Hund’s rule is about filling order/spin in degenerate orbitals; the $ \downarrow\downarrow $ is invalid, and the single $ \uparrow $ is in a context where others are paired incorrectly).

So the configurations that violate Hund’s rule are the second, third, and fourth rows (and the first does not).

# Answer:
The configurations that violate Hund's rule are:
- The second row (with $ \uparrow\quad\uparrow\quad\uparrow\downarrow $)
- The third row (with $ \uparrow\quad\uparrow\quad\downarrow\quad\uparrow\quad\uparrow $)
- The fourth row (with $ \uparrow\downarrow\quad\uparrow\downarrow\quad\downarrow\downarrow\quad\uparrow\downarrow\quad\uparrow $)

(In the given interface, you would check the boxes for the second, third, and fourth rows. The first row does not violate Hund’s rule.)

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Analyzing each option:

Correct Violations:

Answer: