Question

the short form electron configuration of ruthenium is kr4d^{7}5s^{1}, according to hunds rule, use “↑”or“↓” to correctly fill the following diagram. kr 5s 4d choose the correct answer in the following choice. a ↑, ↑↓, ↑↓, ↑↓, ↑ b ↑, ↑↓, ↑↓, ↑, ↑, ↑ c ↑↓, ↑↓, ↑↓, ↑↓ d ↑↓, ↑↓, ↑↓, ↑ e ↑↓, ↑↓, ↑↓, ↑, ↑

Explanation:

Step1: Recall Hund's Rule

Hund's rule states that electrons will first singly occupy degenerate orbitals with parallel spins before pairing up.

Step2: Analyze 5s and 4d orbitals

The 5s orbital has 1 electron, so it is $\uparrow$. The 4d sub - shell has 5 orbitals and 7 electrons. First, 5 electrons singly occupy the 5 4d orbitals with parallel spins ($\uparrow$), and then the remaining 2 electrons pair up with 2 of the singly - occupied orbitals. So the configuration for 5s and 4d is $\uparrow,\uparrow\downarrow,\uparrow,\uparrow,\uparrow,\uparrow$.

Answer:

b. $\uparrow,\uparrow\downarrow,\uparrow,\uparrow,\uparrow,\uparrow$