Chemistry - GENERAL CHEMISTRY Question with Solution | TestHub

To find the value of $|X-Y|$:

Calculate $X$: Species larger than Na⁺ (which is small due to its +1 charge and 10e⁻ configuration) are Cl⁻, H⁻, O²⁻, C⁴⁻, Se²⁻, I⁻, and neutral Ca (total $X=7$), while Mg²⁺ and Al³⁺ are smaller due to higher nuclear charge.

Calculate $Y$: In the 8ᵗʰ period, the subshells filled are $8s$, $5g$, $6f$, $7d$, and $8p$, containing a total of $1+9+7+5+3=25$ orbitals. Since each orbital holds $4e^{-}$, the total elements are $Y=25\times 4=100$.

Final Answer: $|X-Y|=|7-100|=93.00$.