Chemistry - Atomic Structure Question with Solution | TestHub

To solve for $\frac{x+y}{2}$, we first determine the values of $x$ and $y$:

Find $x$: Li²⁺ is a hydrogen-like (single-electron) species. In such systems, the energy of an orbital depends only on the principal quantum number ($n$).

Ground state: $n=1$

1ˢᵗ excited state: $n=2$

2ⁿᵈ excited state: $n=3$

For a given $n$, the number of degenerate orbitals is $n^2$. Thus, for $n=3$, $x=3^2=9$.

Find $y$: The most electronegative element on the Pauling scale is Fluorine (F), which has an electronegativity value of approximately $4.0$.

Calculation:

$$\frac{x+y}{2}=\frac{9+4}{2}=6.5$$